Cathode corrosion protection system and method

Abstract

To provide a system that comprises a cathodic protection system configured to protect a protected structure from corrosion.SOLUTION: A system comprises a cathodic protection system having an anode and configured to protect a protected structure from corrosion. The system comprises a monitoring circuit operatively coupled to the cathodic protection system. The monitoring circuit comprises an electrical-to-optical transducer. The electrical-to-optical transducer is configured to generate a light signal in response to electrical current flowing between the protected structure and the anode of the cathodic protection system, between the protected structure and a reference electrode, or between the reference electrode and the anode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a cathode corrosion protection system and method. [Background technology]

[0002] Metal structures spontaneously oxidize when oxygen and common electrolytes such as water or soil are present. Oxidation causes metals to take the form of oxides (e.g., rust), which can then disintegrate and lead to structural failure. This process is called corrosion and affects bridges, tanks, pipelines, seawalls, and other civil engineering structures. The cost of corrosion was estimated at 2.7% of US GDP, or $450 billion, in 2013. Cathode protection (CP) systems prevent corrosion by providing an energy input in the form of an electric current from a more electrically active metal (sacrificial anode) or a DC power source (applied current). Monitoring how well CP systems are working can be difficult because inspection is challenging, as the structure / anode may be buried in soil, submerged in water, or covered in concrete. [Overview of the project]

[0003] Some embodiments relate to a system including a cathode protection system having an anode and configured to protect a structure to be protected from corrosion. The system includes a monitoring circuit operably coupled to the cathode protection system. The monitoring circuit includes an electro-optic transducer. The electro-optic transducer is configured to generate an optical signal in response to a current flowing between the structure to be protected and the anode of the cathode protection system, between the structure to be protected and a reference electrode, or between the reference electrode and the anode.

[0004] Some embodiments describe methods for protecting a structure to be protected from corrosion using a cathode protection system including an anode. The method includes monitoring corrosion in the structure to be protected using a monitoring circuit including an electro-optic transducer. The method also includes generating an optical signal using the electro-optic transducer in response to a current flowing between the structure to be protected and the anode, between the structure to be protected and a reference electrode, or between the reference electrode and the anode. The method further includes communicating the optical signal to a remote data acquisition system via an optical fiber link.

[0005] The above summary is not intended to describe each of the disclosed embodiments or all practices of this disclosure. The drawings and the following detailed description illustrate exemplary embodiments more specifically. [Brief explanation of the drawing]

[0006] [Figure 1] This figure shows a system comprising a CP system configured to protect a structure to be protected from corrosion, wherein the CP system includes an electrical-optical transducer, according to various embodiments. [Figure 2] This figure shows typical electro-optic transducers for CP systems configured to protect structures from corrosion, according to various embodiments. [Figure 3] This figure shows a system comprising a CP system configured to protect a structure to be protected from corrosion, wherein the CP system includes an electrical-optical transducer, according to various embodiments. [Figure 4] This figure shows a system comprising a CP system configured to protect a structure to be protected from corrosion, wherein the CP system includes an electrical-optical transducer, according to various embodiments. [Figure 5]This figure shows a system comprising a CP system configured to protect a structure to be protected from corrosion, wherein the CP system comprises an electro-optical transducer configured to communicate optical signals to a remote data acquisition system / analyzer. [Figure 6] This is a process flow diagram including a CP system in various embodiments. [Figure 7] This figure shows circuits of electric-optical transducers according to various embodiments. [Figure 8A] This figure shows various encoding schemes for encoding optical signals generated by an electric-optical transducer, according to various embodiments. [Figure 8B] This figure shows various encoding schemes for encoding optical signals generated by an electric-optical transducer, according to various embodiments. [Figure 8C] This figure shows various encoding schemes for encoding optical signals generated by an electric-optical transducer, according to various embodiments. [Figure 8D] This figure shows various encoding schemes for encoding optical signals generated by an electric-optical transducer, according to various embodiments. [Figure 8E] This figure shows various encoding schemes for encoding optical signals generated by an electric-optical transducer, according to various embodiments. [Figure 9] This figure shows experimental demonstrations of sacrificial anode-based CP systems in several embodiments, demonstrating that the CP system includes an electrical-optical transducer. The drawings are not necessarily to scale. Similar numbers used in the drawings refer to similar components. However, it should be understood that the use of numbers referring to components in a given drawing is not intended to limit components in other drawings labeled with the same numbers. [Modes for carrying out the invention]

[0007] A wide variety of electrochemical sensors exist for monitoring corrosion based on open-circuit potential, surface potential, concrete resistivity, polarization resistance, noise analysis, and galvanic current. These approaches are hampered by durability, sensitivity to electromagnetic interference (EMI), and stability issues on very long timescales (>25 years) related to the lifespan of civil engineering structures.

[0008] Embodiments of this disclosure relate to systems and methods for monitoring the status of a CP system. These embodiments of this disclosure differ from conventional electrochemical sensors in that the corrosion signal detected by the CP circuit is converted into an optical signal transmitted via an optical fiber, which is a detection and transmission method that is stable over long time scales in harsh environments and unaffected by EMI. For example, commercial off-the-shelf (COTS) telecommunications-grade laser diodes have a lifespan of 10^6 hours (>100 years).

[0009] Corrosion detection using fiber optic sensors based on fiber Bragg gratings (FBGs) has been demonstrated due to their robustness, EMI resistance, and ease of multiplexing into arrays. However, because FBGs are sensitive only to strain and temperature, they are difficult to combine with processes associated with corrosion. Embodiments of this disclosure differ from FBG-based fiber sensors in that the FBG is a passive element, whereas with FBG sensors, optical pulses are injected externally and specific spectral components are reflected back. According to various embodiments, there is no FBG, and the optical signal can be generated directly using at least a portion of the current from the CP system. In some implementations, optical pulses may be injected externally to supply power (e.g., fiber optic feeding or POF) and / or trigger the start of measurement. It should be noted that fiber optic current sensors based on the Faraday effect are not sufficiently sensitive to measure small currents associated with corrosion.

[0010] Sacrificial anodes with built-in current monitors are commercially available and can form part of remote monitoring cathode protection (RMCP) systems. These conventional systems communicate with a base station via wired or wireless connections. Such systems are powered via solar, wind, or rectifier (for applied current). In some cases, the RMCP node is equipped with a GSM or satellite transmitter to transmit information about the node's status wirelessly.

[0011] Embodiments of this disclosure differ from those systems in that corrosion signals are converted into optical signals and transmitted via optical fibers. Compared to commercial RCMP systems, optical fiber transmission provides a method for transmitting signals over long distances (10-100 km) with low loss, suitable for buried / submerged structures such as pipelines, tanks, bridge piers, and breakwaters. Wireless GSM or satellite signals cannot propagate over long distances underground or underwater due to absorption. Fiber optic connections also provide power to sensors (e.g., using POF configurations) for transmitting trigger signals and for multiplexing with existing fiber infrastructure, including other sensors.

[0012] Embodiments of the present disclosure relate to a system and method for measuring the current flowing through a cathode corrosion protection system using an optical transducer at least partially powered by a CP system. A cathode corrosion protection system slows or stops corrosion by making the structure to be protected (e.g., steel) the cathode in an electrochemical circuit, thereby allowing electrons to flow from the anode to the steel. This requires an energy input. The energy is supplied either by a spontaneous electron flow from a more active "sacrificial" anode (see Figure 1) or by an electron flow from an inactive anode powered by a DC power supply "applied current" (see Figure 3). The circuit is completed by an electrolyte such as water, soil, or concrete between the cathode and anode.

[0013] A unique aspect of the present disclosure is to arrange a light source (e.g., a laser diode or an LED) in series with a CP circuit shown in a figure that generates light when current flows. The optical signal generated by the light source can be communicated to a remote data acquisition system / analyzer via an optical fiber link. One or more characteristics of the optical signal can be analyzed to determine the presence and degree of corrosion in the protected structure (e.g., a steel structure).

[0014] FIG. 1 shows a system 100 according to various embodiments. The system 100 includes a CP system 101 that includes an anode 102 configured to protect a protected structure 104 from corrosion. The anode 102 and the protected structure 104 are disposed in or surrounded by an environment that includes an electrolyte 105 such as water (e.g., salt water), soil, or concrete and an oxidizing agent such as air. The protected structure 104 can take many forms, such as any structure or component made of steel or other metal that is subject to corrosion (e.g., refer to the examples disclosed herein). In the embodiment shown in FIG. 1, the anode 102 is a sacrificial anode made of a suitable material such as Zn, Al, Mg, or an alloy of these metals. The sacrificial material of the anode 102 corrodes in place of the metal of the protected structure 104.

[0015] The system 100 also includes a monitoring circuit 110 operably coupled to the CP system 101. The monitoring circuit 110 includes an electro-optical transducer 112. By way of example, referring to FIG. 2, the electro-optical transducer 112 can include, for example, an LED, a laser diode, or a superluminescent device. As shown in FIGS. 1 and 2 (and other figures), the electro-optical transducer 112 is in series with the anode 102 and the protected structure 104 via electrical connections 106, 108.

[0016] The electro-optical transducer 112 is configured to generate an optical signal 114 in response to a current flowing between the sacrificial anode 102 of the CP system 101 and the anti-corrosion structure 104. As will be described below, the optical signal 114 is communicated to a data acquisition system / analyzer via an optical fiber link. The data acquisition system / analyzer is typically located at a monitoring station remote from the system 100.

[0017] As best shown in FIG. 1 and during operation of the system 100, a corrosion protection current flows between the sacrificial anode 102 and the anti-corrosion structure 104 due to a chemical reaction between the anode 102 and the surrounding environment, causing the anti-corrosion structure 104 to function as a cathode. More specifically, in the electrochemical cell configuration shown in FIG. 1, oxidation is concentrated in the sacrificial anode 102 (electron donor), which releases electrons that flow to the anti-corrosion structure 104, and this becomes the cathode (electron acceptor) in the electrochemical circuit. When electrons accumulate in the anti-corrosion structure 104, the electrochemical potential decreases, thus slowing down or stopping the corrosion of the anti-corrosion structure 104. The sacrificial anode 102 can have various shapes and sizes, such as, for example, wires, rods, tubes, plates, sticks, etc.

[0018] In the case of a sacrificial anode CP system as shown in FIG. 1, the driving voltage is set by the galvanic series shown in Table 1 below, supplying 0.25 - 1.55 V.

[0019]

Table 1

[0020] The ICCP system 201 includes an inert anode 202 and a DC power supply 115 electrically connected to the device to be protected 104. The inert anode 202 is driven by a DC current supplied by the DC power supply 115. The DC power supply 115, which may be called a rectifier, is configured to create a high potential difference between the surface of the structure to be protected 104 and the inert anode 202. The DC power supply 115 is used to generate a current, which provides cathode protection to the structure to be protected 104. It should be noted that when a large current is required for cathode protection, an applied current system yields better results than those associated with sacrificial CP systems.

[0021] For applied current, the voltage is set by the DC power supply 115 and may be 24V or higher. The current flowing through the circuit is determined by the resistivity of the electrolyte 105. The NACE specification for a structure considered corrosion-protected is -850mV vs. the potential of the copper sulfate electrode. If the negative potential value is too large (e.g., <-1V vs. Ag / AgCl), the structure to be protected may be over-protected, the coating may deteriorate, and the structure may weaken due to hydrogen embrittlement. A typical applied current required to protect a steel structure from corrosion is approximately 22mA / m 2 That is the case.

[0022] System 200 also includes a monitoring circuit 110 operably coupled to CP system 201. The monitoring circuit 110 includes a DC power supply 115, an anode 202, and an electro-optical transducer 112 coupled in series with the corrosion-protected structure 104 via electrical connections 106, 108. The electro-optical transducer 112 may include, for example, an LED, a laser diode, or a superluminescent device. As previously stated, the electro-optical transducer 112 is configured to generate an optical signal 114 in response to the current flowing between the corrosion-protected structure 104 and the sacrificial anode 202 of CP system 201. The optical signal 114 is communicated to a data acquisition system / analyzer via an optical fiber link. The data acquisition system is typically located at a monitoring station away from system 200.

[0023] Figures 4 and 5 show the system 300 in various embodiments. In some implementations, the system 300 may be configured as a sacrificial CP system, such that anode 102 is a sacrificial anode as described above. In other implementations, the system 300 may be configured as an applied current CP system, such that anode 202 is an inert anode as described above. The system 300 includes an electrical-optical transducer 112 and a monitoring circuit 110 including a coupling circuit 302.

[0024] As shown in the figure, the coupling circuit 302 is electrically coupled to the anodes 102 / 202 and the corrosion-protected structure 104 via electrical connections 106 and 108. The coupling circuit 302 is also electrically coupled to the electro-optic transducer 112. The coupling circuit 302 may include a voltage converter configured to boost the voltage generated in response to the current flowing between the corrosion-protected structure 104 and the anodes 102 / 202. The voltage converter of the coupling circuit 302 may be configured to drive the electro-optic transducer 112 with the boosted voltage.

[0025] According to some embodiments, the system 300 may include a power subsystem 304. The power subsystem 304 may be configured to supply power to the monitoring system 110. For example, the power subsystem 304 may include an energy harvesting device. According to various embodiments, the energy harvesting device may include one or more of the following: a solar cell circuit, a thermoelectric circuit, a piezoelectric circuit, and a hysteresis circuit configured to harvest energy from galvanic corrosion. The power subsystem 304 may include an energy storage device coupled to receive and store energy from the energy harvesting device. The energy storage device may include one or both of a battery and / or a capacitor (e.g., a supercapacitor).

[0026] Energy harvesting device circuits can boost low-voltage signals from energy harvesting devices by combining energy storage elements such as capacitors with DC-DC converters. The stored energy can be used to generate short bursts of power for acquiring and transmitting data in the form of optical signals 114. Commercial energy harvesting / power management ICs can operate with input voltages as low as 0.020V and generate output voltages of 3.3V or higher (reducing the average current accordingly).

[0027] Furthermore, as shown in Figure 5, the system 300 includes an optical fiber 502 optically coupled to the light source of the electrical-optical transducer 112. The optical fiber 502 is configured to communicate the optical signal 114 generated by the electrical-optical transducer 112 to the data acquisition system / analyzer 506. The optical fiber 502 may be a single-mode or multimode optical fiber. As mentioned above, the optical fiber 502 can communicate the optical signal 114 to the remote data acquisition system / analyzer 506 over a considerable distance (e.g., up to about 100 km without amplification). The data acquisition system / analyzer 506 may be coupled to or incorporated into an optical-electric transducer 504 configured to convert the optical signal 114 into a corresponding electrical signal.

[0028] In some embodiments, the power subsystem 304 may include an optical fiber power supply configured to convert optical energy transmitted through the optical fiber 502 into electrical energy. The electrical energy converted from optical energy is used to power the monitoring circuit 110. As previously mentioned, the optical signal 114 generated by the electrical-optical transducer 112 is communicated to the remote data acquisition system via the optical fiber link 502. This same optical fiber link 502 may be used as the optical link for the optical fiber power supply.

[0029] The semiconductor light source of the electro-optic transducer 112 converts electric current into light. A suitable semiconductor light source is a commercially available telecom laser diode operating at 1550 nm with a forward voltage of 1 V, a threshold current of 10 mA, and an electro-optical conversion efficiency of approximately 3%. The low threshold 850 nm VCSEL under study has a threshold of <1 with a drive voltage of <2 V. This drive voltage and current are widely compatible with the power supplied by the cathode corrosion protection system (~1 V, 10 mA). The power consumption of the laser diode is approximately 20 mW (for example, this is compared to a wireless GSM transmitter requiring >1000 mW in a remote location).

[0030] According to some embodiments, the CP system of the present disclosure may provide sufficient power to operate a laser diode as an electro-optic transducer 112. Some embodiments of the present disclosure aim to collect a portion of the electrical energy from the CP system to drive a light source in order to sense the state of the CP system. For example, by light emission, the current flowing from the anode to the cathode may be read. This provides both a qualitative verification that the circuit is complete and a quantitative measure of the degree of environmental corrosion (e.g., more corrosion leads to more current flow and more light emission).

[0031] Figure 6 is a process flow diagram including the CP system of the present disclosure in various embodiments. The process flow 600 shown in Figure 6 includes a current flow 602 between the anode, the structure to be protected, and, if present, a reference electrode. In the most common case, the coupling circuit may be between any pair of anode / structure, anode / reference electrode, or structure / reference electrode. For example, referring to a modified version of Figure 5, assume that anodes 102 / 202 are labeled as placeholder electrode 1 and structure to be protected 104 is labeled as placeholder electrode 2. In this exemplary example, the values ​​of each placeholder are either an anode, a structure, or a reference electrode. In this exemplary example, the electro-optic transducer is configured to generate an optical signal in response to the current flowing between the structure to be protected and the anode of the cathode protection system, between the structure to be protected and the reference electrode, or between the reference electrode and the anode.

[0032] The process flow 600 also includes energy harvesting and power management 602, which are typically implemented by coupling circuits of the CP system. The process flow 600 further includes encoding an electrical signal 606 indicating the flow of current between the anode and the corrosion-protected structure. The encoded electrical signal is communicated to an electrical-optical transducer 608, which converts the encoded electrical signal into a corresponding optical signal. The optical signal is transmitted to a data acquisition and control facility 612 via an optical fiber link 610.

[0033] The data acquisition and control facility 612 typically includes an analyzer (see, for example, block 506 in Figure 5) and is configured to analyze optical signals to determine the presence and extent of corrosion occurring in the structure being protected from corrosion. The data acquisition and control facility 612 may also communicate control signals to the energy harvesting and power management facility 604 via the optical fiber link 610. In such a configuration, the energy harvesting and power management facility 604 includes an optical-electric transducer. In some embodiments, optical energy may be transmitted via the optical fiber link 610 to supply power to the energy harvesting and power management facility 604 via an optical fiber power supply configuration.

[0034] Figure 7 shows circuits of an electric-optic transducer according to various embodiments. The electric-optic transducer 112 controls the current I flowing between the anode and the corrosion-protected structure of the CP system. corr The current source 702 is proportional to the current I. The electric-optic transducer 112 includes a capacitor 704 in series with a voltage-controlled switch 706, a current-limiting resistor 708, and a light-emitting element 710. corr Corrosion current I corr The capacitor 704 is charged at a charging speed proportional to the voltage. When the capacitor 704 reaches level V switch When charged to this level, switch 706 closes, and capacitor 704 charges through current-limiting resistor 708 (Q=V switch * C) is discharged, causing the light emitter 710 to generate an optical pulse. The circuit of the electro-optic transducer 112 can be implemented in various forms to encode the optical signal generated by the light emitter 710, examples of which are described below.

[0035] In some implementations, the voltage-controlled switch 706 can be closed by coupling it to a solar cell. In some implementations, an optical pulse (e.g., a trigger stimulus) can be sent to the electro-optic transducer 112 via an optical fiber link that closes the voltage-controlled switch 706 and discharges the capacitor 704. Thus, data is read from the electro-optic transducer 112 only when triggered. Consequently, the power consumption of the entire CP system is extremely low.

[0036] Figure 8 shows various encoding schemes for encoding the optical signal generated by the electric-optic transducer 112 according to various embodiments. Figure 8 shows the current I flowing between the anode and the corrosion-protected structure of the CP system as described above. corrBased on the detection, four different encoding methods for generating encoded optical signals of different forms are shown (see FIGS. 7 and 8A). FIG. 8B shows direct analog encoding such as amplitude modulation (AM). In this encoding method, the optical signal shown in FIG. 8B is proportional to the corrosion current I corr is proportional to

[0037] FIG. 8C shows frequency modulation (FM) encoding. The optical signal shown in FIG. 8C consists of a series of pulses, and the pulse repetition rate is proportional to the corrosion current I corr is proportional to. FIG. 8D shows pulse width modulation (PWM) encoding. The optical signal shown in FIG. 8D consists of a series of pulses whose pulse width is proportional to the corrosion current I corr is proportional to. FIG. 8E shows digital encoding. The optical signal shown in FIG. 8E consists of a series of digital words. The value encoded in the digital word is proportional to the corrosion current I corr is proportional to. For example, the 4-bit word 0000 may be equal to a corrosion current of 0 mA, and the 4-bit word 1111 may be equal to a corrosion current of 16 mA.

[0038] Example 1 FIG. 9 shows an experimental demonstration of a sacrificial anode-based PC system monitor. Two beakers 902, 904 containing samples of steel wool 903, 905 were prepared (cathode area ~ 1 m2). In one beaker 902, the steel wool 903 was wired to a sacrificial anode 906 (Mg alloy) via a DC-DC boost converter 910 and separated by a salt bridge 908 to separate any Mg reaction products from the steel reaction products. At time t = 0, a 3% NaCl solution (equivalent to seawater) was poured into both beakers 902, 904, and the LED 912 was lit. After 24 hours, the LED 912 was still lit. The unprotected steel 905 was clearly corroded, but the protected steel 903 was not corroded.

[0039] In conclusion, both Mg sacrificial anodes 906 protected the steel wool 903, causing the LED 912 to light up, positively indicating that the steel wool 903 was protected (or, alternatively, that the beaker was filled with electrolyte and the circuit was complete). This was a somewhat impractical demonstration, as Mg in seawater (high conductivity) with a short path length (low resistance) (high drive voltage) supplied a very large current, over-protecting the steel wool 903. In actual monitoring systems, power management or an external power supply would be useful, as a sacrificial anode more suited to the environment (e.g., Mg in high-resistance soil, Zn in seawater) would generate a smaller current that can be supplied via the same fiber as the readout signal (e.g., via an optical fiber power supply configuration).

[0040] Example 2 As an example of use, in sacrificial anode systems, both the steel and the anode are embedded, making them difficult to access and thus difficult or impossible to inspect. In this case, a laser diode and single-mode fiber can be installed in the electrical path connecting the anode to the steel during anode installation. By coupling the laser diode to a single-mode fiber, the fiber can be deployed to the ground during anode installation and connected to a test station several kilometers away. During its normal lifespan, the anode supplies the electrons that cause the laser diode to emit light. When the sacrificial anode is consumed, the current flow stops, the laser diode stops emitting light, and it indicates that the anode needs to be replaced. Both types of cathode corrosion protection systems (sacrificial anode and applied current) are frequently deployed in arrays of many anodes, and 1550nm laser diodes can be easily multiplexed via single-mode fiber and wavelength division multiplexing, effectively covering the entire structure and allowing identification of which sections are corroding most rapidly. This makes it possible to make effective use of limited inspection time.

[0041] Example 3 One common application of sacrificial anodes is in water heaters. The high temperatures inside water heaters create a corrosive environment, so sacrificial anodes are typically installed to prevent corrosion and eventual rupture of the water heater tank. The sacrificial CP system of this disclosure can be implemented in water heaters.

[0042] Example 4 Apart from detecting the state of the anode, another way to implement various embodiments of this disclosure is to detect changes in the electrolyte. For example, some transformers are buried in underground storage and protected from corrosion via one or more sacrificial anodes. In this configuration, the electrolyte that completes the CP circuit is air or dry soil, which has low conductivity and therefore a low corrosion rate. If the storage is filled with seawater due to extreme weather such as a hurricane, the conductivity of the electrolyte increases, more current flows through the circuit, and the light source lights up. This can be detected by informing technicians of the presence of seawater in the storage through an indicator light on the surface. This detection system does not rely on external power and may be relevant after extreme weather events that do not have power. The same methodology could be applied to detect saltwater intrusion into wells or aquifers, where a sudden increase in conductivity could trigger an alarm. Currently, saltwater intrusion is measured intermittently using groundwater samples or aerial surveys. Embodiments of this disclosure may provide an effective approach to continuously monitor saltwater intrusion.

[0043] This specification refers to the accompanying set of drawings that form part of this disclosure, and at least those skilled in the art will understand that various adaptations and modifications of the embodiments described herein are within the scope of this disclosure or do not depart from it. For example, the embodiments described herein can be combined with each other in various ways. Therefore, it should be understood that within the scope of the appended claims, the claimed invention may be practiced in ways other than those expressly described herein.

[0044] All references and publications cited herein are expressly incorporated by reference, except to the extent that they would directly contradict this disclosure. Unless otherwise indicated, all numbers used herein and in the claims to represent feature sizes, quantities, and physical properties should be understood to be modified by the terms “exactly” or “about.” Thus, unless otherwise indicated, the numerical parameters described in the foregoing specification and the appended claims are approximations that may vary depending on the desired properties sought by a person skilled in the art using the teachings disclosed herein, or approximations within a typical range of experimental error.

[0045] Numerical ranges indicated by endpoints include all numbers contained within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. In this specification, terms modifying a number, such as "at most" or "less than" (for example, "at most 50"), include that number (for example, 50), and terms modifying a number, such as "greater than or equal to" (for example, "greater than or equal to 5"), include that number (for example, 5).

[0046] The terms “combined” or “connected” refer to elements that are attached to each other either directly (in direct contact with each other) or indirectly (having one or more elements between two elements, thus attaching the two elements). Both terms may be modified by “operatively” and “operably,” which can be used interchangeably to describe that the combination or connection is configured to allow the components to interact in order to perform at least some function (for example, a wireless chip may be operably coupled to an antenna element to provide radio frequency electrical signals for wireless communication).

[0047] The orientation terms such as “top,” “bottom,” “side,” and “end” are used to describe the relative positions of the components and are not intended to limit the orientation of the intended embodiment. For example, an embodiment described as having a “top” and a “bottom” also includes that embodiment rotated in various directions unless the content explicitly indicates otherwise.

[0048] References to “one embodiment,” “embodiment,” “a particular embodiment,” or “some embodiments” mean that certain features, configurations, compositions, or properties described in relation to this embodiment are included in at least one embodiment of this disclosure. Therefore, occurrences of such phrases in various places throughout this disclosure do not necessarily refer to the same embodiment. Furthermore, certain features, configurations, compositions, or properties may be combined in any preferred manner in one or more embodiments.

[0049] The terms “preferred” and “preferred” refer to embodiments of the disclosure that may provide a particular benefit under certain circumstances. However, other embodiments may be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unhelpful or that they are not intended to be excluded from the scope of the disclosure.

[0050] As used herein and in the appended claims, the singular forms "a," "an," and "the" encompass embodiments having multiple references unless the content explicitly indicates otherwise. As used herein and in the appended claims, the term "or" is generally adopted to mean "and / or" unless the content explicitly indicates otherwise.

[0051] As used herein, "have," "having," "include," "including," "comprise," and "comprising" are used in an open-ended sense, generally meaning "to include, but not limited to." "Essentially composed of," "composed of," etc., will be understood to be encompassed by "comprising," etc. The term "and / or" means one or all of the enumerated elements, or at least two of the enumerated elements.

[0052] The phrases "at least one," "having at least one of," and "one or more of" used in lists refer to any one of the items in the list, or any combination of two or more items in the list.

Claims

1. A cathode corrosion protection system equipped with an anode and configured to protect the structure to be protected from corrosion, A monitoring circuit for corrosion in the structure to be protected, including an electro-optic transducer operably coupled to the cathode corrosion protection system, which includes a current source proportional to the current associated with the corrosion of the structure to be protected, Equipped with, The electrical-optical transducer is configured to generate an optical signal in response to a current flowing between the structure to be protected from corrosion and the anode of the cathode protection system, or in response to a current flowing between the structure to be protected from corrosion and a reference electrode, or in response to a current flowing between the reference electrode and the anode. The monitoring circuit further includes a coupling circuit including a voltage converter that electrically couples the anode and the corrosion-protected structure via an electrical connection, and the voltage converter The voltage generated in accordance with the current is increased, The boosted voltage drives the electro-optic transducer. A system that is configured in such a way.

2. The system according to claim 1, wherein the anode is a sacrificial anode configured to supply electrons for the current.

3. The system according to claim 1, wherein the anode is an inert anode, and the cathode corrosion protection system comprises a power source that supplies electrons for the current.

4. The system according to claim 1, wherein the electrical-optical transducer is in series between the anode and the structure to be protected from corrosion.

5. The system according to claim 1, further comprising a power subsystem configured to supply power to the system for boosting the voltage.

6. The power subsystem, Solar cell circuit and Thermoelectric circuits and, Piezoelectric circuit and A circuit configured to generate energy from galvanic corrosion, The system according to claim 5, comprising an energy harvesting device having one or more of the following:

7. The system according to claim 6, wherein the power subsystem includes an energy storage device coupled to receive and store energy from the energy harvesting device, and the energy storage device comprises either a battery or a capacitor or both.

8. The system according to claim 5, wherein the power subsystem comprises an optical fiber power supply device configured to convert optical energy transmitted by optical fibers into electrical energy using an energy harvesting device.

9. The system according to claim 1, wherein the electrical-optical transducer comprises at least one of a light-emitting diode, a laser diode, and a superluminescent device.

10. The system according to claim 1, wherein the electrical-optical transducer includes or is coupled to an encoder, and the encoder is configured to encode the optical signal according to a predetermined encoding scheme including amplitude modulation coding, frequency modulation coding, pulse width modulation coding, and digital coding.

11. The system according to claim 1, further comprising a data acquisition circuit optically coupled to the electrical-optical transducer via an optical fiber link, wherein the data acquisition circuit includes an analyzer configured to use the optical signal to measure the presence and extent of corrosion in the structure to be protected from corrosion.

12. The system according to claim 1, wherein the electrical-optical transducer is configured to generate the optical signal in response to the incoming optical pulse.

13. The system according to claim 1, wherein the electrical-optical transducer is configured to generate the optical signal in response to an optical pulse received from the remote data acquisition system via an optical fiber link between the remote data acquisition system and the electrical-optical transducer.

14. Using a cathode corrosion protection system that includes an anode, the structure to be protected is protected from corrosion, The corrosion in the corrosion-protected structure is monitored using a monitoring circuit that includes an electric-optical transducer containing a current source proportional to the current generated by the corrosion of the corrosion-protected structure, The electrical-optical transducer generates an optical signal in accordance with the current flowing between the corrosion-protected structure and the anode, in accordance with the current flowing between the corrosion-protected structure and the reference electrode, or in accordance with the current flowing between the reference electrode and the anode. Using a voltage converter, the voltage generated according to the current is boosted, The boosted voltage is used to drive the electric-optical transducer, The optical signal is communicated to a remote data acquisition system via an optical fiber link, Methods that include...

15. The method according to claim 14, wherein the anode is a sacrificial anode.

16. The method according to claim 14, wherein the anode is an inert anode.

17. The method according to claim 14, comprising using an energy harvesting device to generate power for the monitoring circuit.

18. The method according to claim 14, comprising encoding the optical signal according to a predetermined encoding scheme including amplitude modulation encoding, frequency modulation encoding, pulse width modulation encoding, and digital encoding to generate an encoded optical signal.

19. The method according to claim 18, further comprising using the encoded optical signal to measure the presence and extent of corrosion in the corrosion-protected structure using the remote data acquisition system.

20. The method according to claim 14, wherein the optical signal is generated in response to the transmitted optical pulse.

21. The method according to claim 14, wherein the electrical-optical transducer generates the optical signal in response to an optical pulse received from the remote data acquisition system via the optical fiber link between the remote data acquisition system and the electrical-optical transducer.

22. A cathode corrosion protection system equipped with an anode and configured to protect the structure to be protected from corrosion, A monitoring circuit operably coupled to the cathode corrosion protection system, the monitoring circuit for corrosion in the corrosion-protected structure, comprising an electro-optic transducer including a current source proportional to the current associated with the corrosion of the corrosion-protected structure, An electric-optical transducer configured to generate an optical signal in accordance with the current flowing between the corrosion-protected structure and the anode of the cathode corrosion protection system, or in accordance with the current flowing between the corrosion-protected structure and the reference electrode, or in accordance with the current flowing between the reference electrode and the anode, Equipped with, A system in which the electrical-optical transducer includes or is coupled to an encoder, and the encoder is configured to encode the optical signal according to a predetermined encoding scheme, which includes amplitude modulation coding, frequency modulation coding, pulse width modulation coding, and digital coding.

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