An early warning system for the detachment of an insulating coating of an alkaline water electrolyzer polar plate

Abstract

The utility model discloses a kind of alkali water electrolytic cell polar plate insulating coating peeling early warning system, including the flexible grid pressure-sensitive resistance film pre-buried in polar plate outer edge surface insulating coating, the optical fiber sensor pre-buried in polar plate outer edge surface insulating coating, resistance value data acquisition module, optical signal data acquisition module, optical signal data of optical fiber sensor and the monitoring early warning system containing analysis and alarm module, monitoring early warning system is according to resistance value data and optical signal data analysis and judge whether coating peeling condition occurs, and alarm signal is sent when coating peeling;Flexible grid pressure-sensitive resistance film is connected resistance value data acquisition module by resistance data lead-out wire, optical fiber sensor is connected optical signal data acquisition module by optical signal data lead-out wire, resistance value data acquisition module, optical signal data acquisition module are respectively connected monitoring early warning system.The utility model realizes the on-line real-time monitoring and initiative early warning of electrolytic cell polar plate insulating coating state.

Description

Technical Field

[0001] This utility model relates to the field of alkaline water electrolysis cell technology, specifically to an early warning system and method for the peeling of insulating coating on the electrode plates of an alkaline water electrolysis cell. Background Technology

[0002] The alkaline water electrolyzer is the core equipment for producing hydrogen through water electrolysis. It is a combination of devices that uses alkaline water as raw material to produce hydrogen through water electrolysis. The electrode plates of the alkaline water electrolyzer are the charged components of the alkaline water electrolyzer, which include the electrode frame and the main electrode plate connected within the electrode frame. The outer periphery of the electrode frame is called the outer edge of the electrode plate (when the electrode plate is circular, its outer edge is called the outer circle of the electrode plate), and its surface is coated with an epoxy resin coating to achieve insulation and safety protection.

[0003] However, existing alkaline water-based hydrogen production electrolyzers still have the following problems:

[0004] First, the electrodes in existing alkaline water electrolyzers are exposed to high current density, highly corrosive electrolyte, and high temperature and humidity environments for extended periods, which can easily lead to damage or peeling of the insulating coating on the outer edge of the electrodes. Once the coating is damaged or peeled off, the metal substrate at the outer edge of the electrodes will be exposed due to the small spacing between the electrodes (usually only 2-3 mm). This may cause metal impurities (such as detached welding slag) to fall accidentally and cause a short circuit between the outer edges of adjacent electrodes. On the one hand, this leads to a decrease in electrolysis efficiency, shunting of short-circuit current, reduction of effective electrolysis current, and an increase in energy consumption of 10% to 30%. On the other hand, it may also lead to safety problems such as fire and overheating caused by short circuits.

[0005] Secondly, the uneven thickness (usually 50~200 μm) of the insulating coating on the outer edge of the electrode plate makes the weak areas of the coating more susceptible to peeling under thermal stress, further increasing the possibility of coating detachment or damage and creating safety hazards.

[0006] Third, the existing technology lacks an efficient coating peeling monitoring mechanism for the insulating coating on the outer edge of the electrode plate. It usually relies on periodic shutdown inspections (such as high voltage withstand voltage tests), which are costly to maintain. Furthermore, traditional manual inspections are unable to detect micron-level coating damage, resulting in a delayed fault response.

[0007] Therefore, it is necessary to develop an early warning system and method for the peeling of the insulating coating on the electrode plates of an alkaline water electrolyzer to solve the above problems. Utility Model Content

[0008] To address the aforementioned problems, this invention proposes a system and method for early warning of electrode insulation coating peeling in alkaline water electrolyzers. The aim is to overcome the shortcomings of existing technologies and achieve online real-time monitoring and proactive early warning of the state of the electrode insulation coating in alkaline water electrolyzers. The specific technical solution is as follows:

[0009] An early warning system for the peeling of the insulating coating on the electrode plates of an alkaline water electrolyzer includes:

[0010] A flexible mesh-like varistor film is embedded in the insulating coating on the outer edge of the electrode plate to monitor coating peeling.

[0011] An optical fiber sensor embedded in the insulating coating on the outer edge of the electrode plate is used to monitor stress changes in the insulating coating.

[0012] A resistance data acquisition module is used to acquire the resistance data of the flexible mesh-like varistor film;

[0013] The optical signal data acquisition module is used to send, acquire, retrieve, and process the optical signal data transmitted by the optical fiber sensor.

[0014] A monitoring and early warning system including an analysis and alarm module is used to collect and process the resistance value data and optical signal data, analyze and determine whether coating peeling has occurred based on the resistance value data and optical signal data, and issue an alarm signal when coating peeling occurs.

[0015] The flexible mesh-shaped varistor film is connected to the resistance value data acquisition module via a resistance data lead-out line, and the optical fiber sensor is connected to the optical signal data acquisition module via an optical signal data lead-out line. The resistance value data acquisition module and the optical signal data acquisition module are respectively connected to the monitoring and early warning system.

[0016] When the coating peels off, the stress generated by the peeling will act on the flexible mesh varistor film, causing the resistance of the flexible mesh varistor film to change. Therefore, when the resistance change of the flexible mesh varistor film exceeds the set threshold, the monitoring and early warning system determines that there may be a coating peeling situation.

[0017] In addition, when the coating peels off, the stress generated by the peeling will also act on the optical fiber of the fiber optic sensor, causing an increase in local strain on the fiber optic sensor. The fiber optic sensor can detect these strain changes, and the monitoring and early warning system can accurately locate the location of the coating peeling off based on the optical signal data and the changes in the optical signal measured by the fiber optic sensor.

[0018] In this invention, the insulating coating of the alkaline water electrolysis cell electrode plate is a composite coating, which sequentially includes a substrate transition layer, an intermediate layer and a surface layer. The flexible mesh-shaped varistor film and the fiber optic sensor are respectively embedded between the intermediate layer and the surface layer, and the coating material of the coating adjacent to the flexible mesh-shaped varistor film penetrates and fills into the mesh space of the flexible mesh-shaped varistor film.

[0019] Preferably, the substrate transition layer uses a conductive microporous nickel layer with a thickness of 20-50 μm, which is formed by electroplating to enhance the adhesion of the coating, and its bonding strength is ≥15 MPa; the intermediate layer uses an epoxy resin-silicon carbide composite coating with a thickness of 150-300 μm and a silicon carbide content of 10%-20% to provide insulation, wear resistance and alkali resistance, and its pH is >14; the surface layer uses an insulating polyaniline (PANI) coating with a thickness of 20-50 μm.

[0020] In this invention, the outer edge surface of the electrode plate of the alkaline water electrolyzer is divided into N monitoring areas along the circumferential direction. There are N flexible mesh-shaped varistor films, and the N flexible mesh-shaped varistor films are pre-embedded in the insulating coating of the N monitoring areas, thereby forming a zoned monitoring of the peeling of the insulating coating of the electrode plate of the alkaline water electrolyzer.

[0021] When the change in resistance of the flexible mesh varistor film exceeds the set threshold, the monitoring and early warning system issues an early warning signal for coating peeling. The monitoring and early warning system also reports the specific area information of the coating peeling location on the outer circumference of the electrode plate according to the partition location of the flexible mesh varistor film where the resistance has changed, so that maintenance personnel can carry out timely and targeted coating repair.

[0022] Preferably, the flexible mesh-like varistor film is made of a conductive polymer material and formed into a mesh structure with a line width of 0.1 mm and a spacing of no more than 5 mm through a screen printing process. Each mesh unit is a varistor unit. When the coating peels off, stress is generated and acts on the flexible mesh-like varistor film, changing the conductivity inside the flexible mesh-like varistor film, thereby causing a sudden change in the resistance of the flexible mesh-like varistor film.

[0023] Preferably, the fiber optic sensor is a multi-axis fiber grating sensor with multi-directional sensing capability or an OFDR fiber optic sensor with higher positioning accuracy for optical signal changes; the optical fibers of the fiber optic sensor are arranged in a serpentine pattern along the circumference of the electrode plate in the coating of the alkaline water electrolysis cell, and the optical fibers of the fiber optic sensor arranged in a serpentine pattern are interwoven and woven into the grid space of the flexible mesh-like varistor film along the serpentine path.

[0024] The aforementioned serpentine arrangement of the optical fiber sensor increases the monitoring density and range of the optical fiber sensor on the electrode coating. Furthermore, since the optical fiber of the serpentine arrangement is interwoven and woven into the grid space of the flexible mesh varistor film, the flexible mesh varistor film and the optical fiber sensor can simultaneously monitor the coating peeling at the same location, thereby increasing the accuracy of coating peeling monitoring.

[0025] In this invention, the resistance value data acquisition module includes an ADC analog-to-digital converter, a voltage divider circuit, and a multiplexer. The flexible mesh-shaped varistor film located in each zone on each plate is connected to the ADC analog-to-digital converter through the multiplexer, and the ADC analog-to-digital converter is connected to the monitoring and early warning system. When the fiber optic sensor is an OFDR fiber optic sensor, the optical signal data acquisition module includes an OFDR fiber optic demodulator. The fiber optic cable of the fiber optic sensor is connected to the OFDR fiber optic demodulator, and the OFDR fiber optic demodulator is connected to the monitoring and early warning system.

[0026] The OFDR demodulator is used to acquire the strain distribution along the optical fiber; the multiplexer is used to select flexible mesh varistor films in different zones; and the ADC analog-to-digital converter is used to convert the resistance value of the flexible mesh varistor film into a digital signal for processing by the monitoring and early warning system (host computer).

[0027] The use of a multiplexer in the resistance data acquisition module can reduce the number of wires required from multiple flexible mesh varistor film partitions to the monitoring device, simplifying wiring complexity and reducing system costs.

[0028] As a further improvement, the alkaline water electrolysis cell electrode plate insulation coating peeling early warning system of this utility model is further provided with a coating peeling detection enhancement module. The coating peeling detection enhancement module includes microcapsules dispersed in the surface coating. The microcapsules are at least one of the following: microcapsules containing conductive nanomaterials, microcapsules containing fluorescent nanomaterials, and microcapsules containing magnetic nanomaterials. When the coating partially peels off or cracks, the microcapsules rupture and release the nanomaterials, which penetrate into the flexible mesh varistor film or attach to the optical fiber of the optical fiber sensor. This causes a sudden change in the resistance of the flexible mesh varistor film or changes the dielectric properties around the optical fiber of the optical fiber sensor, resulting in a sudden change in the optical signal of the optical fiber sensor. Through the sudden change in the resistance of the flexible mesh varistor film and the sudden change in the optical signal of the optical fiber sensor, the sensitivity and reliability of coating peeling monitoring are enhanced.

[0029] Preferably, the microcapsules are not only dispersed in the surface coating, but also dispersed in the intermediate coating.

[0030] The microcapsules in this invention adopt a double-layer or multi-layer structure design. The outer layer is a protective layer to ensure that it will not rupture and release under normal conditions; the inner layer contains nanomaterials with specific functions.

[0031] Preferably, the microcapsules are 5 to 50 μm in size, uniformly dispersed in the coating, and the rupture threshold is designed to be slightly lower than the coating peel strength to ensure activation at the stage of slight damage.

[0032] Preferably, the conductive nanomaterials in the microcapsules can be silver nanoparticles, copper nanoparticles, or carbon nanotubes, which have extremely high conductivity. After the microcapsules rupture, they penetrate into the varistor grid, which can significantly improve local conductivity and response speed, thereby enhancing the overall sensitivity of the flexible grid-like varistor film. Alternatively, the conductive nanomaterials can be polyaniline nanoparticles or polypyrrole nanoparticles, which not only have good conductivity but also a certain degree of flexibility. They can fill the cracks and form new conductive paths, thereby enhancing the overall sensitivity of the flexible grid-like varistor film.

[0033] Preferably, the conductive nanomaterial in the microcapsule is a wet conductive nanomaterial carrying a conductive liquid (such as conductive ionized water) to further extend its conductivity. When the coating peels off, the released wet conductive nanomaterial utilizes its wet properties to expand the conductive area, further improving conductivity.

[0034] Preferably, the conductive nanomaterials in the microcapsules can be replaced with a conductive liquid to form microcapsules containing a conductive liquid, which have good conductivity and low cost.

[0035] Preferably, the fluorescent nanomaterials in the microcapsules are quantum dots (QDs): as fluorescent markers, when the microcapsules rupture, the quantum dots are released and come into contact with the surface of the optical fiber. By absorbing and re-emitting light, they can change the refractive index of the medium surrounding the optical fiber, thereby affecting the OFDR signal and enhancing the sensitivity and reliability of coating peeling monitoring.

[0036] Preferably, the magnetic nanomaterial in the microcapsule can be Fe3O4 nanoparticles, which can not only indirectly affect the strain sensing capability of the optical fiber by changing the magnetic field distribution around the optical fiber, but also affect its optical properties by changing the dielectric constant around the optical fiber, thereby enhancing the sensitivity and reliability of coating peeling monitoring.

[0037] When the coating peels off, causing the microcapsules containing conductive nanomaterials to rupture, the released conductive nanomaterials infiltrate into the flexible mesh varistor film, thereby increasing the conductive path of the flexible mesh varistor film and causing a significant drop in the resistance of the flexible mesh varistor film. The monitoring and early warning system can identify the region of the flexible mesh varistor film where the resistance drops significantly, and this region is the region where the coating peeled off.

[0038] When the coating peels off, causing the microcapsules containing fluorescent nanomaterials to rupture, the released fluorescent nanomaterials (quantum dots) will generate a strong fluorescence signal under a low excitation light intensity. This directly changes the refractive index of the medium surrounding the optical fiber of the fiber optic sensor, thereby significantly reducing the intensity of the received optical fiber sensing signal. The specific location of the coating peeling can be identified and located through a monitoring and early warning system.

[0039] When the coating peels off, causing the microcapsules containing magnetic nanomaterials to rupture, the released magnetic nanomaterials are exposed on the surface of the optical fiber, thereby changing the magnetic properties of the medium surrounding the optical fiber. The change in refractive index caused by the change in magnetic field leads to more light leakage or scattering, which significantly reduces the intensity of backscattered light received by the OFDR system. The specific location of the coating peeling can be identified and located by the monitoring and early warning system.

[0040] Preferably, the nanomaterials contained in the microcapsules have a size of 5~50 μm and are uniformly dispersed in the coating, and the rupture threshold of the microcapsules is lower than the peel strength of the coating.

[0041] The various microcapsules in this invention can be used individually or in combination according to actual needs to achieve synergistic enhancement of the monitoring of flexible mesh-like varistor films and fiber optic sensing signals, thereby improving the performance of the entire monitoring and early warning system.

[0042] Preferably, the alkaline water electrolysis cell is further equipped with a temperature sensor for detecting the surface temperature of the electrode coating. The temperature sensor is connected to a monitoring and early warning system to compensate for the measurement error of the resistance of the flexible mesh varistor film caused by temperature changes.

[0043] A method for early warning of coating peeling off the electrode plate of an alkaline water electrolyzer includes: embedding a flexible mesh-shaped varistor film in the insulating coating on the outer surface of the electrode plate, and monitoring the resistance of the flexible mesh-shaped varistor film online through a monitoring and early warning system; simultaneously embedding an optical fiber sensor in the insulating coating on the outer surface of the electrode plate, and monitoring the optical signal received by the optical fiber sensor and its changes through the monitoring and early warning system; the monitoring and early warning system uses multi-signal fusion analysis to simultaneously monitor the resistance of the flexible mesh-shaped varistor film and the optical signal received by the optical fiber sensor and its changes; when the change in resistance of the flexible mesh-shaped varistor film and the change in optical signal received by the optical fiber sensor both exceed a set threshold, the monitoring and early warning system issues an early warning signal for coating peeling off; the monitoring and early warning system also locates the area on the outer edge of the electrode plate where the coating peeling off occurs based on the circumferential partitioning position of the flexible mesh-shaped varistor film with the resistance exceeding the threshold; and simultaneously, the monitoring and early warning system also locates the specific location of the coating peeling off based on the optical signal and its changes acquired by the optical fiber sensor.

[0044] As a further improvement, the present invention provides a method for early warning of coating peeling off the electrode plate of an alkaline water electrolysis cell, which further includes microcapsules containing conductive nanomaterials uniformly dispersed in the insulating coating on the outer surface of the electrode plate to enhance the sensitivity of the flexible mesh varistor to resistance changes, and microcapsules containing fluorescent nanomaterials or magnetic nanomaterials uniformly dispersed in the insulating coating on the outer surface of the electrode plate to enhance the sensitivity of the optical signal received by the fiber optic sensor to light signal changes. When the coating peels off, the conductive nanomaterials released by the rupture of the microcapsules incorporating conductive nanomaterials penetrate into the flexible mesh varistor film, thereby increasing the conductive path of the flexible mesh varistor film and causing a significant decrease in the resistance of the flexible mesh varistor film, thus enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling off; the fluorescent nanomaterials released by the rupture of the microcapsules incorporating fluorescent nanomaterials when the coating peels off... The material generates a strong fluorescence signal under low excitation light intensity, directly changing the refractive index of the medium surrounding the optical fiber of the fiber optic sensor, thereby significantly reducing the intensity of the received optical fiber sensing signal. The monitoring and early warning system identifies and locates the coating peeling location based on the optical signal data and changes in the optical signal measured by the fiber optic sensor, thus further enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling. When the coating peels off, the microcapsules containing magnetic nanomaterials rupture, releasing magnetic nanomaterials that are exposed on the surface of the optical fiber, thereby changing the magnetic properties of the medium surrounding the optical fiber. The change in refractive index caused by the change in magnetic field leads to more light leakage or scattering, significantly reducing the intensity of backscattered light received by the OFDR system in the monitoring and early warning system. Thus, the OFDR system can identify and accurately locate the coating peeling location, thereby further enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling.

[0045] Preferably, the monitoring and early warning system uses multi-signal fusion analysis to simultaneously process changes in the resistance of the flexible mesh-like varistor film and changes in the optical signal caused by sudden stress changes in the fiber optic sensor due to coating peeling. If both the resistance exceeds a specified threshold (e.g., resistance drop rate > 90%) and the optical signal change exceeds a specified threshold, then coating peeling is determined. Furthermore, it implements a graded alarm function. In the case of a Level 1 alarm (single-point anomaly), the monitoring and early warning system prompts the inspection of a designated location area. In the case of a Level 2 alarm (multi-point anomaly), the alkaline water electrolysis cell automatically reduces its load and the monitoring and early warning system triggers an audible and visual alarm.

[0046] The beneficial effects of this utility model are:

[0047] First, the present invention provides an early warning system and method for the detachment of insulating coating on the electrode plate of an alkaline water electrolyzer. The insulating coating on the outer edge of the electrode plate integrates a flexible mesh-shaped varistor film and an optical fiber sensor. By utilizing the change in electrical characteristics (resistance) of the flexible mesh-shaped varistor film when the coating detaches, and the change in optical signal caused by the stress deformation of the optical fiber during coating detachment, an online dual monitoring and early warning mechanism for coating detachment events on the electrode plate is realized, and its coating detachment monitoring has good reliability.

[0048] Secondly, this utility model discloses an early warning system and method for the peeling of insulating coating on the electrode plates of an alkaline water electrolysis cell. The innovative flexible mesh-like varistor film has a large monitoring coverage area.

[0049] The outer edge of the electrode plate is divided into sections, and a corresponding flexible mesh-like varistor film is set in the coating of each section. This greatly reduces the number of resistor leads and can locate the specific section where the coating has fallen off. Furthermore, by combining the monitoring results of the fiber optic sensor, the precise location of the coating fall-off can be achieved.

[0050] Third, the alkaline water electrolysis cell electrode plate insulation coating peeling early warning system and method of this utility model is equipped with a coating peeling detection enhancement module. Through the microcapsule enhanced detection mechanism, it causes a sudden change in the resistance of the flexible mesh varistor film and a sudden change in the optical signal of the fiber optic sensor when the coating peels off, thereby significantly enhancing the sensitivity and reliability of coating peeling monitoring.

[0051] Fourth, the present invention provides an early warning system and method for the peeling of insulating coating on the electrode plate of an alkaline water electrolyzer. A substrate transition layer is provided on the surface of the metal substrate at the outer edge of the electrode plate. The substrate transition layer uses a conductive microporous nickel layer with a thickness of 20~50 μm, which can improve the coating adhesion by 200%, extend the service life from 2 years to 5 years, and reduce short circuit accidents by 95%.

[0052] Fifth, the present invention provides an early warning system and method for the peeling of insulating coating on the electrode plate of an alkaline water electrolyzer, which can achieve high-precision, real-time online monitoring of the peeling status of the outer edge coating of the electrode plate of the water electrolyzer. Through real-time online monitoring, the specific location of the coating peeling can be quickly and accurately located, facilitating timely repair of the peeled coating, avoiding unplanned downtime, and reducing annual maintenance costs by 40%. Attached Figure Description

[0053] Figure 1 This is a schematic diagram illustrating the overall principle of an early warning system for the peeling of the insulating coating on the electrode plates of an alkaline water electrolysis cell, according to this utility model.

[0054] Figure 2 This is a schematic diagram of the layered structure of the insulating coating on the electrode plates of an alkaline water electrolysis cell;

[0055] Figure 3 A schematic diagram showing the optical fibers of an optical fiber sensor interwoven and woven into the grid space of a flexible mesh-like varistor film in the outer coating of the electrode plate of an alkaline water electrolyzer.

[0056] In the diagram: 1. Electrode, 2. Substrate transition layer, 3. Intermediate layer, 4. Flexible mesh-like varistor film, 5. Surface layer, 6. Optical fiber of the optical fiber sensor, 7. Resistance data lead, 8. Optical signal data lead. Detailed Implementation

[0057] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0058] Example 1:

[0059] like Figures 1 to 3 The image shows an embodiment of an early warning system for the peeling of the insulating coating on the electrode plates of an alkaline water electrolyzer, comprising:

[0060] A flexible mesh-shaped varistor film 4 is embedded in the insulating coating on the outer edge surface of the electrode plate 1 to monitor coating peeling.

[0061] An optical fiber sensor embedded in the insulating coating on the outer edge of electrode plate 1 is used to monitor stress changes in the insulating coating.

[0062] A resistance data acquisition module is used to acquire the resistance data of the flexible mesh-like varistor film;

[0063] The optical signal data acquisition module is used to send, acquire, retrieve, and process the optical signal data transmitted by the optical fiber sensor.

[0064] A monitoring and early warning system including an analysis and alarm module is used to collect and process the resistance value data and optical signal data, analyze and determine whether coating peeling has occurred based on the resistance value data and optical signal data, and issue an alarm signal when coating peeling occurs.

[0065] The flexible mesh-shaped varistor film 4 is connected to the resistance value data acquisition module via resistance data lead-out line 7, and the optical fiber sensor is connected to the optical signal data acquisition module via optical signal data lead-out line 8. The resistance value data acquisition module and the optical signal data acquisition module are respectively connected to the monitoring and early warning system.

[0066] When the coating peels off, the stress generated by the peeling will act on the flexible mesh varistor film 4, causing the resistance of the flexible mesh varistor film 4 to change. Therefore, when the resistance change of the flexible mesh varistor film 4 exceeds the set threshold, the monitoring and early warning system determines that there may be a coating peeling situation.

[0067] In addition, when the coating peels off, the stress generated by the peeling off will also act on the fiber optic sensor's fiber optic 6, causing an increase in local strain on the fiber optic sensor's fiber optic 6. The fiber optic sensor can detect these strain changes, and the monitoring and early warning system can accurately locate the position of the coating peeling off based on the optical signal data measured by the fiber optic sensor and the changes in the optical signal data.

[0068] In this embodiment, the insulating coating of the alkaline water electrolysis cell electrode plate is a composite coating, which includes a substrate transition layer 2, an intermediate layer 3 and a surface layer 4 in sequence. The flexible mesh varistor film 4 and the optical fiber sensor are respectively embedded between the intermediate layer 3 and the surface layer 5, and the coating material of the coating adjacent to the flexible mesh varistor film 4 penetrates and fills into the mesh space of the flexible mesh varistor film 4.

[0069] Preferably, the substrate transition layer uses a conductive microporous nickel layer with a thickness of 20-50 μm, which is formed by electroplating to enhance the adhesion of the coating, and its bonding strength is ≥15 MPa; the intermediate layer uses an epoxy resin-silicon carbide composite coating with a thickness of 150-300 μm and a silicon carbide content of 10%-20% to provide insulation, wear resistance and alkali resistance, and its pH is >14; the surface layer uses an insulating polyaniline (PANI) coating with a thickness of 20-50 μm.

[0070] In this embodiment, the outer edge surface of the electrode plate of the alkaline water electrolyzer is divided into N monitoring areas along the circumferential direction. There are N flexible mesh-shaped varistor films, and the N flexible mesh-shaped varistor films are embedded in the insulating coating of the N monitoring areas, thereby forming a zoned monitoring of the peeling of the insulating coating of the electrode plate of the alkaline water electrolyzer.

[0071] When the change in resistance of the flexible mesh varistor film exceeds the set threshold, the monitoring and early warning system issues an early warning signal for coating peeling. The monitoring and early warning system also reports the specific area information of the coating peeling location on the outer circumference of the electrode plate according to the partition location of the flexible mesh varistor film where the resistance has changed, so that maintenance personnel can carry out timely and targeted coating repair.

[0072] Preferably, the flexible mesh-like varistor film is made of a conductive polymer material and formed into a mesh structure with a line width of 0.1 mm and a spacing of no more than 5 mm through a screen printing process. Each mesh unit is a varistor unit. When the coating peels off, stress is generated and acts on the flexible mesh-like varistor film, changing the conductivity inside the flexible mesh-like varistor film, thereby causing a sudden change in the resistance of the flexible mesh-like varistor film.

[0073] Preferably, the fiber optic sensor is a multi-axis fiber grating sensor with multi-directional sensing capability or an OFDR fiber optic sensor with higher positioning accuracy for optical signal changes; the optical fibers of the fiber optic sensor are arranged in a serpentine pattern along the circumference of the electrode plate in the coating of the alkaline water electrolysis cell, and the optical fibers of the fiber optic sensor arranged in a serpentine pattern are interwoven and woven into the grid space of the flexible mesh-like varistor film along the serpentine path.

[0074] The aforementioned serpentine arrangement of the optical fiber sensor increases the monitoring density and range of the optical fiber sensor on the electrode coating. Furthermore, since the optical fiber of the serpentine arrangement is interwoven and woven into the grid space of the flexible mesh varistor film, the flexible mesh varistor film and the optical fiber sensor can simultaneously monitor the coating peeling at the same location, thereby increasing the accuracy of coating peeling monitoring.

[0075] In this embodiment, the resistance value data acquisition module includes an ADC analog-to-digital converter, a voltage divider circuit, and a multiplexer. The flexible mesh-shaped varistor film located in each partition on each plate is connected to the ADC analog-to-digital converter through the multiplexer. The ADC analog-to-digital converter is connected to the monitoring and early warning system. When the fiber optic sensor is an OFDR fiber optic sensor, the optical signal data acquisition module includes an OFDR fiber optic demodulator. The fiber optic cable of the fiber optic sensor is connected to the OFDR fiber optic demodulator, and the OFDR fiber optic demodulator is connected to the monitoring and early warning system.

[0076] The OFDR demodulator is used to acquire the strain distribution along the optical fiber; the multiplexer is used to select flexible mesh varistor films in different zones; and the ADC analog-to-digital converter is used to convert the resistance value of the flexible mesh varistor film into a digital signal for processing by the monitoring and early warning system (host computer).

[0077] The use of a multiplexer in the resistance data acquisition module can reduce the number of wires required from multiple flexible mesh varistor film partitions to the monitoring device, simplifying wiring complexity and reducing system costs.

[0078] As a further improvement, the alkaline water electrolysis cell electrode plate insulation coating peeling early warning system of this utility model is further provided with a coating peeling detection enhancement module. The coating peeling detection enhancement module includes microcapsules dispersed in the surface coating. The microcapsules are at least one of the following: microcapsules containing conductive nanomaterials, microcapsules containing fluorescent nanomaterials, and microcapsules containing magnetic nanomaterials. When the coating partially peels off or cracks, the microcapsules rupture and release the nanomaterials, which penetrate into the flexible mesh varistor film or attach to the optical fiber of the optical fiber sensor. This causes a sudden change in the resistance of the flexible mesh varistor film or changes the dielectric properties around the optical fiber of the optical fiber sensor, resulting in a sudden change in the optical signal of the optical fiber sensor. Through the sudden change in the resistance of the flexible mesh varistor film and the sudden change in the optical signal of the optical fiber sensor, the sensitivity and reliability of coating peeling monitoring are enhanced.

[0079] Preferably, the microcapsules are not only dispersed in the surface coating, but also dispersed in the intermediate coating.

[0080] The microcapsules in this invention adopt a double-layer or multi-layer structure design. The outer layer is a protective layer to ensure that it will not rupture and release under normal conditions; the inner layer contains nanomaterials with specific functions.

[0081] Preferably, the microcapsules are 5 to 50 μm in size, uniformly dispersed in the coating, and the rupture threshold is designed to be slightly lower than the coating peel strength to ensure activation at the stage of slight damage.

[0082] Preferably, the conductive nanomaterials in the microcapsules can be silver nanoparticles, copper nanoparticles, or carbon nanotubes, which have extremely high conductivity. After the microcapsules rupture, they penetrate into the varistor grid, which can significantly improve local conductivity and response speed, thereby enhancing the overall sensitivity of the flexible grid-like varistor film. Alternatively, the conductive nanomaterials can be polyaniline nanoparticles or polypyrrole nanoparticles, which not only have good conductivity but also a certain degree of flexibility. They can fill the cracks and form new conductive paths, thereby enhancing the overall sensitivity of the flexible grid-like varistor film.

[0083] Preferably, the conductive nanomaterial in the microcapsule is a wet conductive nanomaterial carrying a conductive liquid (such as conductive ionized water) to further extend its conductivity. When the coating peels off, the released wet conductive nanomaterial utilizes its wet properties to expand the conductive area, further improving conductivity.

[0084] Preferably, the conductive nanomaterials in the microcapsules can be replaced with a conductive liquid to form microcapsules containing a conductive liquid, which have good conductivity and low cost.

[0085] Preferably, the fluorescent nanomaterials in the microcapsules are quantum dots (QDs): as fluorescent markers, when the microcapsules rupture, the quantum dots are released and come into contact with the surface of the optical fiber. By absorbing and re-emitting light, they can change the refractive index of the medium surrounding the optical fiber, thereby affecting the OFDR signal and enhancing the sensitivity and reliability of coating peeling monitoring.

[0086] Preferably, the magnetic nanomaterial in the microcapsule can be Fe3O4 nanoparticles, which can not only indirectly affect the strain sensing capability of the optical fiber by changing the magnetic field distribution around the optical fiber, but also affect its optical properties by changing the dielectric constant around the optical fiber, thereby enhancing the sensitivity and reliability of coating peeling monitoring.

[0087] When the coating peels off, causing the microcapsules containing conductive nanomaterials to rupture, the released conductive nanomaterials infiltrate into the flexible mesh varistor film, thereby increasing the conductive path of the flexible mesh varistor film and causing a significant drop in the resistance of the flexible mesh varistor film. The monitoring and early warning system can identify the region of the flexible mesh varistor film where the resistance drops significantly, and this region is the region where the coating peeled off.

[0088] When the coating peels off, causing the microcapsules containing fluorescent nanomaterials to rupture, the released fluorescent nanomaterials (quantum dots) will generate a strong fluorescence signal under a low excitation light intensity. This directly changes the refractive index of the medium surrounding the optical fiber of the fiber optic sensor, thereby significantly reducing the intensity of the received optical fiber sensing signal. The specific location of the coating peeling can be identified and located through a monitoring and early warning system.

[0089] When the coating peels off, causing the microcapsules containing magnetic nanomaterials to rupture, the released magnetic nanomaterials are exposed on the surface of the optical fiber, thereby changing the magnetic properties of the medium surrounding the optical fiber. The change in refractive index caused by the change in magnetic field leads to more light leakage or scattering, which significantly reduces the intensity of backscattered light received by the OFDR system. The specific location of the coating peeling can be identified and located by the monitoring and early warning system.

[0090] Preferably, the nanomaterials contained in the microcapsules have a size of 5~50 μm and are uniformly dispersed in the coating, and the rupture threshold of the microcapsules is lower than the peel strength of the coating.

[0091] The various microcapsules in this embodiment can be used individually or in combination according to actual needs to achieve synergistic enhancement of the monitoring of flexible mesh-like varistor films and fiber optic sensing signals, thereby improving the performance of the entire monitoring and early warning system.

[0092] Preferably, the alkaline water electrolysis cell is further equipped with a temperature sensor for detecting the surface temperature of the electrode coating. The temperature sensor is connected to a monitoring and early warning system to compensate for the measurement error of the resistance of the flexible mesh varistor film caused by temperature changes.

[0093] In this embodiment, the flexible mesh-like varistor film can use PI film as the substrate, with a thickness of 50 μm. The varistor material is carbon black / silicone rubber composite, and a mesh with a line width of 0.1 mm and a spacing of no more than 5 mm is formed by screen printing. The lead-out pads are printed with silver paste and are located on both sides of the film edge.

[0094] In this embodiment, the conductive nanomaterials contained in the microcapsules are prepared by using silver nanoparticles (Ag NPs) with a particle size of about 20 nm. The preparation method is to use emulsion polymerization to disperse the silver nanoparticles in an aqueous phase and use urea-formaldehyde resin as a protective layer to form microcapsules with an average particle size of 20 μm.

[0095] The aforementioned microcapsules containing conductive nanomaterials can be added to the intermediate and top coating layers before coating at a mass ratio of 3% to 5% and dispersed uniformly.

[0096] In this embodiment, the microcapsules containing magnetic nanomaterials are prepared by using Fe3O4 nanoparticles with a particle size of about 10 nm. The preparation method is a chemical coprecipitation method, in which Fe3O4 nanoparticles are dispersed in an aqueous phase and silicon dioxide (SiO2) is used as a protective layer to form microcapsules with an average particle size of 20 μm.

[0097] The aforementioned microcapsules containing magnetic nanomaterials can be added to the intermediate and top coating layers before coating at a mass ratio of 3% to 5% and dispersed uniformly.

[0098] In this embodiment, the microcapsules containing fluorescent nanomaterials are prepared by using CdSe / ZnS core-shell structured quantum dots (QDs) with an emission wavelength of 600 nm. The preparation method is a solvent evaporation method, in which the quantum dots are dispersed in an organic solvent and polyurethane is used as a protective layer to form microcapsules with an average particle size of 20 μm.

[0099] The microcapsules containing fluorescent nanomaterials can be added to the intermediate and top coating layers before coating at a mass ratio of 3% to 5% and dispersed uniformly.

[0100] Example 2:

[0101] A method for early warning of coating peeling off the electrode plate of an alkaline water electrolyzer includes: embedding a flexible mesh-shaped varistor film in the insulating coating on the outer surface of the electrode plate, and monitoring the resistance of the flexible mesh-shaped varistor film online through a monitoring and early warning system; simultaneously embedding an optical fiber sensor in the insulating coating on the outer surface of the electrode plate, and monitoring the optical signal received by the optical fiber sensor and its changes through the monitoring and early warning system; the monitoring and early warning system uses multi-signal fusion analysis to simultaneously monitor the resistance of the flexible mesh-shaped varistor film and the optical signal received by the optical fiber sensor and its changes; when the change in resistance of the flexible mesh-shaped varistor film and the change in optical signal received by the optical fiber sensor both exceed a set threshold, the monitoring and early warning system issues an early warning signal for coating peeling off; the monitoring and early warning system also locates the area on the outer edge of the electrode plate where the coating peeling off occurs based on the circumferential partitioning position of the flexible mesh-shaped varistor film with the resistance exceeding the threshold; and simultaneously, the monitoring and early warning system also locates the specific location of the coating peeling off based on the optical signal and its changes acquired by the optical fiber sensor.

[0102] As a further improvement, the present invention provides a method for early warning of coating peeling off the electrode plate of an alkaline water electrolysis cell, which further includes microcapsules containing conductive nanomaterials uniformly dispersed in the insulating coating on the outer surface of the electrode plate to enhance the sensitivity of the flexible mesh varistor to resistance changes, and microcapsules containing fluorescent nanomaterials or magnetic nanomaterials uniformly dispersed in the insulating coating on the outer surface of the electrode plate to enhance the sensitivity of the optical signal received by the fiber optic sensor to light signal changes. When the coating peels off, the conductive nanomaterials released by the rupture of the microcapsules incorporating conductive nanomaterials penetrate into the flexible mesh varistor film, thereby increasing the conductive path of the flexible mesh varistor film and causing a significant decrease in the resistance of the flexible mesh varistor film, thus enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling off; the fluorescent nanomaterials released by the rupture of the microcapsules incorporating fluorescent nanomaterials when the coating peels off... The material generates a strong fluorescence signal under low excitation light intensity, directly changing the refractive index of the medium surrounding the optical fiber of the fiber optic sensor, thereby significantly reducing the intensity of the received optical fiber sensing signal. The monitoring and early warning system identifies and locates the coating peeling location based on the optical signal data and changes in the optical signal measured by the fiber optic sensor, thus further enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling. When the coating peels off, the microcapsules containing magnetic nanomaterials rupture, releasing magnetic nanomaterials that are exposed on the surface of the optical fiber, thereby changing the magnetic properties of the medium surrounding the optical fiber. The change in refractive index caused by the change in magnetic field leads to more light leakage or scattering, significantly reducing the intensity of backscattered light received by the OFDR system in the monitoring and early warning system. Thus, the OFDR system can identify and accurately locate the coating peeling location, thereby further enhancing the sensitivity and reliability of the monitoring and early warning system in detecting coating peeling.

[0103] Preferably, the monitoring and early warning system uses multi-signal fusion analysis to simultaneously process changes in the resistance of the flexible mesh-like varistor film and changes in the optical signal caused by sudden stress changes in the fiber optic sensor due to coating peeling. If both the resistance exceeds a specified threshold (e.g., resistance drop rate > 90%) and the optical signal change exceeds a specified threshold, then coating peeling is determined. Furthermore, it implements a graded alarm function. In the case of a Level 1 alarm (single-point anomaly), the monitoring and early warning system prompts the inspection of a designated location area. In the case of a Level 2 alarm (multi-point anomaly), the alkaline water electrolysis cell automatically reduces its load and the monitoring and early warning system triggers an audible and visual alarm.

[0104] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A system for early warning of the detachment of an insulating coating of an alkaline water electrolyzer electrode plate, characterized in that, include: A flexible mesh-like varistor film is embedded in the insulating coating on the outer edge of the electrode plate to monitor coating peeling. An optical fiber sensor embedded in the insulating coating on the outer edge of the electrode plate is used to monitor stress changes in the insulating coating. A resistance data acquisition module is used to acquire the resistance data of the flexible mesh-like varistor film; The optical signal data acquisition module is used to send, acquire, retrieve, and process the optical signal data transmitted by the optical fiber sensor. A monitoring and early warning system including an analysis and alarm module is used to collect and process the resistance value data and optical signal data, analyze and determine whether coating peeling has occurred based on the resistance value data and optical signal data, and issue an alarm signal when coating peeling occurs. The flexible mesh-shaped varistor film is connected to the resistance value data acquisition module via a resistance data lead-out line, and the optical fiber sensor is connected to the optical signal data acquisition module via an optical signal data lead-out line. The resistance value data acquisition module and the optical signal data acquisition module are respectively connected to the monitoring and early warning system.

2. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 1, characterized in that, The insulating coating of the alkaline water electrolysis cell electrode plate is a composite coating, which sequentially includes a substrate transition layer, an intermediate layer and a surface layer. The flexible mesh-shaped varistor film and the optical fiber sensor are respectively embedded between the intermediate layer and the surface layer, and the coating material of the coating adjacent to the flexible mesh-shaped varistor film penetrates and fills into the mesh space of the flexible mesh-shaped varistor film.

3. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 2, characterized in that, The substrate transition layer uses a conductive microporous nickel layer with a thickness of 20-50 μm, which is formed by electroplating to enhance the adhesion of the coating, with an adhesion strength ≥15 MPa; the intermediate layer uses an epoxy resin-silicon carbide composite coating with a thickness of 150-300 μm and a silicon carbide content of 10%-20% to provide insulation, wear resistance and alkali resistance, with a pH >14; the surface layer uses an insulating polyaniline (PANI) coating with a thickness of 20-50 μm.

4. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 1, characterized in that, The outer edge surface of the electrode plate of the alkaline water electrolyzer is divided into N monitoring areas along the circumferential direction. There are N flexible mesh-shaped varistor films, and the N flexible mesh-shaped varistor films are pre-embedded in the insulating coating of the N monitoring areas, thereby forming a zoned monitoring of the peeling of the insulating coating of the electrode plate of the alkaline water electrolyzer.

5. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 1, characterized in that, The flexible mesh-shaped varistor film is made of conductive polymer material and is formed into a mesh structure with a line width of 0.1 mm and a spacing of no more than 5 mm by screen printing process. Each mesh unit is a varistor unit. When the coating peels off, the resistance of the flexible mesh-shaped varistor film changes abruptly.

6. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 4, characterized in that, The fiber optic sensor employs a multi-axis fiber grating sensor with multi-directional sensing capability or an OFDR fiber optic sensor with higher positioning accuracy for optical signal changes. The optical fibers of the fiber optic sensor are arranged in a serpentine, meandering pattern along the circumference of the electrode plate in the coating of the alkaline water electrolysis cell, and the optical fibers of the fiber optic sensor, arranged in a serpentine, meandering pattern, are interwoven and woven into the grid space of the flexible mesh-like varistor film along the serpentine, meandering path.

7. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 6, characterized in that, The resistance value data acquisition module includes an ADC analog-to-digital converter, a voltage divider circuit, and a multiplexer. The flexible mesh-shaped varistor film located in each zone on each plate is connected to the ADC analog-to-digital converter through the multiplexer. The ADC analog-to-digital converter is connected to the monitoring and early warning system. When the optical fiber sensor is an OFDR optical fiber sensor, the optical signal data acquisition module includes an OFDR optical fiber demodulator, the optical fiber of the optical fiber sensor is connected to the OFDR optical fiber demodulator, and the OFDR optical fiber demodulator is connected to the monitoring and early warning system.

8. The early warning system for the peeling of the insulating coating on the electrode plate of an alkaline water electrolyzer according to claim 1, characterized in that, A coating peeling detection enhancement module is also provided. This module includes microcapsules dispersed in the surface coating. The microcapsules are at least one of the following: microcapsules containing conductive nanomaterials, microcapsules containing fluorescent nanomaterials, and microcapsules containing magnetic nanomaterials. When the coating partially peels off or cracks, the microcapsules rupture and release the nanomaterials, which then permeate into the flexible mesh varistor film or adhere to the optical fiber of the fiber optic sensor. This causes a sudden change in the resistance of the flexible mesh varistor film or alters the dielectric properties around the optical fiber of the fiber optic sensor, resulting in a sudden change in the optical signal of the fiber optic sensor. Through the sudden change in the resistance of the flexible mesh varistor film and the sudden change in the optical signal of the fiber optic sensor, the sensitivity and reliability of coating peeling detection are enhanced.

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