Water electrolysis cell state in-situ monitoring system and monitoring method

Abstract

The water electrolysis cell state in-situ monitoring system is used for monitoring a PEM water electrolysis device, and comprises a first fiber bragg grating sensor array and a second fiber bragg grating sensor array which are arranged in a polar plate flow channel; the computer is used for analyzing optical signals obtained by the first fiber bragg grating sensor array and the second fiber bragg grating sensor array and displaying the optical signals as temperature field and bubble state information. According to the water electrolysis cell state in-situ monitoring system and method provided by the invention, a temperature field and a stress field in the water electrolysis cell and the state of hydrogen bubbles generated by reaction can be monitored in real time, and multi-area coverage monitoring can be realized through an array formed by sensors, so that the monitored bubble field information is more complete; and meanwhile, the sensitivity performance is improved by coating the metal layer outside the cladding of the inclined gate region.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to an in-situ monitoring system and a monitoring method for a water electrolysis cell state. Background Art

[0002] In recent years, with the greenhouse gas emission problem becoming increasingly serious, hydrogen energy, as a new energy source with the characteristics of stable current, low noise, high efficiency and no greenhouse gas emission, has attracted much attention and become the first choice for countries to develop new energy. PEM water electrolysis technology uses water electrolysis to produce hydrogen. It has the advantages of high gas purity, low energy consumption, high efficiency and compact structure. It is a renewable energy hydrogen production technology with huge industrial application potential and meets the social needs of sustainable development. Therefore, the development of high-performance and low-cost PEM water electrolysis technology has become the goal pursued by many researchers and is also a hot topic in the current academic research.

[0003] The PEM water electrolysis process has very high requirements for bubble management. Water electrolysis usually requires a large current density. A large number of bubbles will be generated on the electrode surface to block the micropores and restrict the water flow. Even the porous structure of the electrode will trap the bubbles, thereby hindering the contact between the electrolyte and the electrode, resulting in abnormal ohmic changes. The current density also changes accordingly, which will eventually reduce the efficiency of water electrolysis to produce hydrogen. In addition, the performance of the PEM water electrolysis cell is affected by many factors, including physical parameters such as temperature and pressure. Therefore, for PEM water electrolysis to produce hydrogen, the ability to monitor the temperature, stress and bubble state generated by the water electrolysis cell in real time under working conditions is conducive to improving the electrolysis cell and increasing the efficiency of hydrogen production.

[0004] Due to the limitation of PEM device structure, the current research on temperature, stress and bubble distribution of PEM water electrolysis devices is mostly limited to simulation, and it is impossible to conduct relevant research through experimental means to effectively monitor its internal state. This situation significantly hinders the in-depth understanding and systematic analysis of its mechanism, and also limits the further development of PEM water electrolysis technology. Summary of the invention

[0005] The present invention aims to solve one of the technical problems existing in the related art at least to a certain extent.

[0006] An object of the present invention is to provide an in-situ monitoring system for the state of a water electrolysis cell, which uses a fiber Bragg grating sensor to effectively monitor the three parameters of temperature, stress and bubble state at key locations in a PEM water electrolysis cell that affect its performance.

[0007] Another object of the present invention is to provide a method for in-situ monitoring of the state of a water electrolysis cell.

[0008] In order to achieve the above-mentioned object, the present invention provides, on one hand, an in-situ monitoring system for the status of a water electrolysis cell, which is used for monitoring a PEM water electrolysis device, wherein the PEM water electrolysis device comprises an electrolysis cell, a plate and a membrane electrode in the electrolysis cell, and an electrochemical workstation electrically connected to the plate; the electrochemical workstation provides a working current for the plate;

[0009] The monitoring system comprises a first fiber Bragg grating sensor array and a second fiber Bragg grating sensor array arranged in a plate flow channel; and:

[0010] A light source, used to provide a light source for the first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array;

[0011] A demodulator connected to the first fiber Bragg grating sensor array to obtain an optical signal of the first fiber Bragg grating sensor array;

[0012] A spectrometer connected to the second fiber Bragg grating sensor array to obtain an optical signal of the second fiber Bragg grating sensor array;

[0013] The computer is connected to the demodulator and the spectrometer for communication, receives and analyzes the optical signals transmitted by the demodulator and the spectrometer, and displays the temperature field, stress field and bubble status information.

[0014] A further preferred technical solution of the present invention is that the first fiber Bragg grating sensor array comprises n fiber Bragg grating sensors, the grating region length of each fiber Bragg grating sensor is 10-15 mm, the central wavelength is 1530-1560 nm, and the grating region is packaged by a capillary quartz tube;

[0015] Each fiber Bragg grating sensor is arranged on the contact surface between the flow channel inside the electrode plate and the membrane electrode.

[0016] Preferably, the demodulator is multi-channel, and its input end is connected to n fiber Bragg grating sensors in the first fiber Bragg grating sensor array through a single-mode optical fiber, and its output end is connected to a computer through a data line, and is used to transmit the spectral wavelength signal of the first fiber Bragg grating sensor array. The computer analyzes the spectral wavelength signal and displays it as a temperature field and a stress field.

[0017] Preferably, the second fiber Bragg grating sensor array comprises m tilted fiber Bragg grating sensors, each tilted fiber Bragg grating sensor has a tilt angle of 4 to 40 degrees, a grating region length of 10 to 15 mm, and a central wavelength of 1545 to 1580 nm;

[0018] Each tilted fiber Bragg grating sensor is arranged at a central position in the electrode plate flow channel.

[0019] Preferably, the spectrometer is multi-channel, and its input end is connected to m tilted fiber Bragg grating sensors of the second fiber Bragg grating sensor array through a single-mode optical fiber, and its output end is connected to a computer through a data line for transmitting the optical power signal of the second fiber Bragg grating sensor array. The computer analyzes the optical power signal and displays it as bubble status information.

[0020] Preferably, the surface of each tilted fiber Bragg grating is coated with 1-50 nm graphene.

[0021] Preferably, the electrochemical workstation provides the voltage-current required for the operation of the electrolytic cell by leading out the positive electrode, the negative electrode and the reference electrode, and is connected to a computer via a data line, and the reaction rate is controlled by setting different voltage-currents by the computer.

[0022] Preferably, the size of the flow channel inside the plate of the electrolytic cell ranges from 20 mm×20 mm to 100 mm×100 mm, and the electrolyte used in the water electrolytic cell is an alkaline solution or an acidic solution;

[0023] The first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array are arranged on the pole plate in a serpentine shape along the flow channel inside the pole plate.

[0024] Preferably, the light source is a broadband light source with a wavelength range of 1300-1600nm.

[0025] Another aspect of the present invention provides a method for in-situ monitoring of the state of a water electrolysis cell, comprising the following steps:

[0026] S1, turning on the electrochemical workstation, providing the current-voltage required by the electrolytic cell, and starting the electrolytic cell to work; during the operation of the electrolytic cell, the temperature of the electrode plate rises, and bubbles are generated in the flow channel inside the electrode plate, and the bubbles flow in the flow channel with the electrolyte and pass through the second fiber Bragg grating sensor array;

[0027] S2. Turn on the light source, which emits a signal light with a wavelength range of 1300-1600nm transmitted through a single-mode optical fiber to the first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array;

[0028] S3. The fiber Bragg gratings in the first fiber Bragg grating sensor array sequentially transmit the specific wavelength signal light transmitted by the light source to the demodulator;

[0029] S4. The demodulator transmits the specific wavelength signal to the computer. Based on the principle that the spectral wavelength signal corresponds to the temperature, the computer processes the spectral wavelength signal and resolves the optical signal obtained by the first fiber Bragg grating sensor array into temperature information and stress information, thereby realizing in-situ monitoring of the temperature field and stress field state inside the water electrolysis cell;

[0030] S5. The tilted fiber Bragg grating in the second fiber Bragg grating sensor array sequentially transmits the optical signal transmitted by the light source to the spectrometer;

[0031] S6. The spectrometer transmits the optical power signal to the computer. Based on the principle that the optical power signal corresponds to the bubble state, the computer processes the optical power signal into a change in the refractive index of the gas-liquid two phases in the electrolyte in the electrolytic cell, thereby realizing in-situ monitoring of the bubble state generated in the electrolytic cell.

[0032] Beneficial effects: The in-situ monitoring system and method of the water electrolysis cell state of the present invention realizes temperature and stress monitoring of key positions such as plates and membrane electrodes that have a greater impact on the performance of the PEM water electrolysis cell in a PEM water electrolysis cell device through a fiber Bragg grating sensor; at the same time, in-situ monitoring is performed in the PEM water electrolysis cell device through a sensitive tilted fiber Bragg grating sensor, thereby realizing the monitoring of the "gas-liquid" two-phase refractive index and the evolution process of bubbles in the reaction fluid flow channel; further, the two sensors are used in an array to form a fiber Bragg grating sensor array system and a tilted fiber Bragg grating sensor array system, so that the monitoring information is more comprehensive, and finally the effective monitoring of the three parameters of temperature, stress and bubble state of the position that affects the performance of the PEM water electrolysis cell under working conditions is realized.

[0033] In addition, the tilted fiber Bragg grating array sensing system of the present invention is equipped with a graphene film on the basis of the existing tilted fiber Bragg grating sensor, and utilizes the SPR effect to enhance the sensitivity to the environmental refractive index and improve the perception of the bubble state in the PEM water electrolysis cell device. And through the design of the array, the key positions in the PEM water electrolysis cell are fully covered, and the real-time monitoring effect of the temperature field, stress field, and bubble field is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the in-situ monitoring system of the water electrolysis cell state of the present invention;

[0035] Figure 2 A schematic diagram of the layout of a first fiber Bragg grating sensor array and a second fiber Bragg grating sensor array in an embodiment of the present invention;

[0036] Figure 3 is a transmission spectrum of the tilted fiber Bragg grating sensor of the present invention;

[0037] Figure 4 It is a transmission spectrum diagram of the tilted fiber Bragg grating sensor of the present invention in an electrolyte and bubble environment;

[0038] Figure 5 The figure is a transmission spectrum diagram of the tilted fiber Bragg grating sensor of the present invention for cladding modes with different numbers of bubbles with a diameter of 190 um in a three-electrode water electrolysis cell.

[0039] In the figure, 1. PEM water electrolysis device; 1-1. electrode plate; 1-2. membrane electrode; 1-3. gasket; 2. light source; 3. first fiber Bragg grating sensor array; 4. second fiber Bragg grating sensor array; 5. electrochemical workstation; 6. demodulator; 7. spectrometer; 8. computer. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, and they should not be understood as limitations on the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be understood that the terms used are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] Combine the following Figure 1-Figure 5 The invention describes an in-situ monitoring system and method for the status of a water electrolysis cell.

[0042] Embodiment 1: This embodiment provides an in-situ monitoring system for the state of a water electrolysis cell, which is used for monitoring a PEM water electrolysis device 1, wherein the PEM water electrolysis device 1 comprises an electrolysis cell, a plate 1-3, a membrane electrode 1-1 and a gasket 1-2 located in the electrolysis cell, the plate 1-3 being connected to an electrochemical workstation 5 by an alligator clip at the end of a transmission line, and the electrochemical workstation 5 providing the voltage-current required for the PEM water electrolysis operation. The flow channel size of the inner side of the plate 1-3 ranges from 20 mm×20 mm to 100 mm×100 mm, and the electrolyte used in the water electrolysis cell is an alkaline solution or an acidic solution.

[0043] Monitoring systems, such as Figure 1As shown, it includes a first fiber Bragg grating sensor array 3, a second fiber Bragg grating sensor array 4, a light source 2, a demodulator 6, a spectrometer 7 and a computer 8. Among them, the light source 2 is a broadband light source with a wavelength of 1560nm. The first fiber Bragg grating sensor array 3 and the second fiber Bragg grating sensor array 4 are placed in the flow channel of the plate 1-3. The first fiber Bragg grating sensor array 3 is connected to the light source 2 through one end of a common single-mode optical fiber, and the other end is connected to the input port of the demodulator 6. The second fiber Bragg grating sensor array 4 is connected to the light source 2 through one end of a common single-mode optical fiber, and the other end is connected to the input port of the spectrometer 7. The demodulator 6 and the spectrometer 7 are connected to the computer 8 through a data line. The computer 8 is used to analyze the spectral signal and display it as intuitive temperature field, stress field and bubble state information.

[0044] Specifically, Figure 2 As shown, in this embodiment, the first fiber Bragg grating sensor array 3 is composed of 12 fiber Bragg grating sensors spaced 5 mm apart from each other. The grating area length of each fiber Bragg grating sensor is 12 mm, the central wavelength is 1560 nm, and the grating area is packaged with a capillary quartz tube. The second fiber Bragg grating sensor array 4 is composed of 12 tilted fiber Bragg grating sensors, each tilted fiber Bragg grating sensor has an inclination angle of 20 degrees, a grating area length of 12 mm, and a central wavelength of 1560 nm. The two sensor arrays are arranged in parallel and serpentine on the pole plate 1-3. Each fiber Bragg grating sensor is arranged on the contact surface between the inner flow channel of the pole plate 1-3 and the membrane electrode 1-1. Each tilted fiber Bragg grating sensor is arranged in the center of the flow channel of the pole plate 1-3. The fiber Bragg grating array is fixed to the pole plate 1-3 by ceramic glue between the two fiber Bragg grating sensors in each column, that is, in the middle position of each column, and is also fixed to the pole plate 1-3 by ceramic glue at each turning position.

[0045] The first fiber Bragg grating sensor array 3 is connected by an ordinary single-mode optical fiber. The single-mode optical fiber passes through a hollow steel needle, and the hollow steel needle passes through a gasket 1-2 and the exit position is fixed by ceramic glue. The single-mode optical fiber passing through the steel needle is connected to the input port of the demodulator 6, and the demodulator 6 is connected to the computer 8 through a data line. The computer 8 is used to analyze the spectral signal and display it as an intuitive temperature field and stress field. The 12 tilted fiber Bragg grating sensors of the second fiber Bragg grating sensor array 4 are 45nm graphene-coated enhanced tilted fiber Bragg gratings. Single-mode optical fibers are fused at both ends of the enhanced tilted fiber Bragg grating. The single-mode optical fiber passes through a hollow steel needle, and the hollow steel needle passes through a gasket 1-2 and the exit position is fixed by ceramic glue. The single-mode optical fiber at one end is connected to the light source 2, and the single-mode optical fiber at the other end is connected to the input port of the spectrometer 7. The spectrometer 7 is connected to the computer 8 through a data line. The computer 8 is used to analyze the spectral signal and display it as bubble status information. As Figure 3As shown, the transmission spectrum of the second fiber Bragg grating sensor array 4 during the water electrolysis process is shown.

[0046] In this embodiment, the plate 1-3 is a conductor, connected by the crocodile clips at the ends of the positive and negative wires drawn from the electrochemical workstation 5, wherein the red crocodile clip is connected to the positive electrode of the plate 1-3, and the black crocodile clip is connected to the negative electrode of the plate 1-3. The electrochemical workstation 5 provides the voltage-current required for the operation of the electrolytic cell by drawing out the positive electrode, the negative electrode and the reference electrode. The electrochemical workstation 5 is connected to the computer 8 via a data line, and different voltages and currents can be set at the computer 8 end to control the reaction rate. As the reaction proceeds, changes in temperature and stress occur at the corresponding positions of the PME water electrolysis cell, and bubbles are generated in the flow channel, and the refractive index changes. At this time, the changes in these parameters will be monitored by the first fiber Bragg grating sensor array 3 and the second fiber Bragg grating sensor array 4 and displayed in the form of optical signals on the demodulator 6 and the spectrometer 7, respectively, and finally input to the computer 8 through the data line, and processed by it as temperature, stress and bubble state information.

[0047] Embodiment 2: This embodiment provides a method for in-situ monitoring of the state of a water electrolysis cell, comprising the following steps:

[0048] S1, start the electrochemical workstation 5, provide the current-voltage required by the electrolytic cell, and start the electrolytic cell to work; during the operation of the electrolytic cell, the temperature of the electrode plates 1-3 rises, and bubbles are generated in the flow channel inside the electrode plates 1-3, and the bubbles flow in the flow channel with the electrolyte and pass through the second fiber Bragg grating sensor array 4;

[0049] S2. Turn on the light source 2, which emits a signal light with a wavelength of 1560 nm transmitted through a single-mode optical fiber to the first fiber Bragg grating sensor array 3 and the second fiber Bragg grating sensor array 4;

[0050] S3. The fiber Bragg gratings in the first fiber Bragg grating sensor array 3 sequentially transmit the specific wavelength signal light transmitted by the light source 2 to the demodulator 6;

[0051] S4. The demodulator 6 transmits the specific wavelength signal to the computer 8. Based on the principle that the spectral wavelength signal corresponds to the temperature, the computer 8 processes the spectral wavelength signal and resolves the optical signal obtained by the first fiber Bragg grating sensor array 3 into temperature information and stress information, thereby realizing in-situ monitoring of the temperature field and stress field state inside the water electrolysis cell;

[0052] S5. The tilted fiber Bragg grating in the second fiber Bragg grating sensor array 4 sequentially transmits the optical signal transmitted by the light source 2 to the spectrometer 7;

[0053] S6. The spectrometer 7 transmits the optical power signal to the computer 8. Based on the principle that the optical power signal corresponds to the state of the bubble, the computer 8 processes the optical power signal into a change in the refractive index of the gas-liquid two phases in the electrolyte in the electrolytic cell, such as Figure 4 As shown, it is a transmission spectrum diagram of the sensor of the present invention in an electrolyte and bubble environment, which realizes in-situ monitoring of the state of bubbles generated in the electrolytic cell.

[0054] The first fiber Bragg grating sensor array 3 of this embodiment is composed of 12 fiber Bragg gratings encapsulated in capillary quartz tubes, which can isolate stress and monitor the temperature field at the positions of the plates 1-3 in real time. The second fiber Bragg grating sensor array 4 is composed of 12 tilted fiber Bragg gratings, which monitor the coupling information of the temperature field and stress field at the positions of the plates 1-3 in real time. Taking a certain position as an example, the sensor in the first fiber Bragg grating sensor array 3 is named FBG1. FBG1 is affected by strain and temperature, and the corresponding reflection wavelength can be expressed as follows:

[0055] Δλ FBG1 =k ε1 Δε+k T1 ΔT

[0056] The sensor in the second fiber Bragg grating sensor array 4 is FBG2. For FBG2 without strain effect, the wavelength change effect caused by temperature can be expressed as:

[0057] Δλ FBG2 =k T2 ΔT

[0058] In the formula, k ε1 is the strain sensitivity of FBG1, k T1 is the temperature sensitivity of FBG1, Δε is the strain change, and ΔT is the temperature change; k T2 is the temperature sensitivity of FBG2, ΔT is the temperature change. If the sensitivity is known, the strain Δε can be accurately calculated.

[0059]

[0060] The intensified tilted fiber Bragg grating in the second fiber Bragg grating sensor array 4 can sensitively monitor the change of refractive index. When bubbles are generated in the flow channel inside the electrode plate 1-3, part of the KOH solution in contact with the sensing area will be occupied by the bubbles. The refractive index of the environment is different for different bubble sizes, and the spectral signals displayed by the corresponding demodulator 6 are also different. Finally, the specific information of the bubbles is obtained through analysis and processing by the computer 8. The transmission spectrum of the sensor in the water electrolysis cell for the cladding mode of different numbers of bubbles with a diameter of 190um is shown in the figure: Figure 5 .

[0061] The fiber Bragg grating and the sensitized tilted fiber Bragg grating are engraved by hydrogen-loaded photosensitive fiber in a 248nm ArF excimer laser system. The repetition frequency of the laser is 20Hz, the output voltage is 23KV, and the single pulse energy is 100mJ. The laser converges a beam of uniform light through the optical path to the phase mask template for beam splitting interference, thereby forming an interference pattern. The long-term exposure of the fiber core to these interference patterns will cause the core refractive index to change periodically, thereby forming a grating area. After the phase mask template is tilted at an angle, a tilted fiber Bragg grating is engraved.

[0062] The layout positions and quantities of the fiber Bragg grating array and the tilted fiber Bragg grating can be adjusted as needed, so that the monitoring of the temperature field, the stress field and the bubble state can be changed according to actual needs.

[0063] The working principle of the present invention is as follows: the electrochemical workstation 5 provides the voltage and current required for the operation of the PEM water electrolysis cell. When the PEM water electrolysis cell is operating, hydrogen bubbles flowing along the serpentine flow channel will be generated, accompanied by heat and deformation (stress). The first fiber Bragg grating array and the second fiber Bragg grating array are sensitive to the temperature and stress generated during the reaction. The demodulator 6 transmits the optical signal to the computer 8 for processing, and finally obtains the temperature field and stress field information. A tilted fiber Bragg grating sensor is arranged in the flow channel, which is sensitive to the change of refractive index. When bubbles are generated, the environment near the tilted fiber Bragg grating changes from electrolyte to bubbles, and the refractive index of the gas-liquid two-phase environment is different. The corresponding optical signal appears on the transmission spectrum of the spectrometer 7, and the spectrometer 7 hands the signal to the computer 8 for signal processing, which is finally displayed as the size and number of bubbles.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water electrolysis cell state in-situ monitoring system for monitoring a PEM water electrolysis device, the PEM water electrolysis device comprising an electrolysis cell, a plate and a membrane electrode in the electrolysis cell, and an electrochemical workstation electrically connected to the plate; the electrochemical workstation provides a working current for the plate; characterized in that: The monitoring system includes a first fiber Bragg grating sensor array and a second fiber Bragg grating sensor array arranged in a plate flow channel; as well as: A light source, used to provide a light source for the first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array; A demodulator connected to the first fiber Bragg grating sensor array to obtain an optical signal of the first fiber Bragg grating sensor array; A spectrometer connected to the second fiber Bragg grating sensor array to obtain an optical signal of the second fiber Bragg grating sensor array; The computer is connected to the demodulator and the spectrometer for communication, receives and analyzes the optical signals transmitted by the demodulator and the spectrometer, and displays the temperature field, stress field and bubble status information.

2. The water electrolysis cell status in-situ monitoring system according to claim 1, characterized in that: The first fiber Bragg grating sensor array comprises n fiber Bragg grating sensors, each fiber Bragg grating sensor has a grating region length of 10-15 mm, a central wavelength of 1530-1560 nm, and the grating region is packaged in a capillary quartz tube; Each fiber Bragg grating sensor is arranged on the contact surface between the flow channel inside the electrode plate and the membrane electrode.

3. The water electrolysis cell status in-situ monitoring system according to claim 2, characterized in that: The demodulator is multi-channel, and its input end is connected to n fiber Bragg grating sensors in the first fiber Bragg grating sensor array through a single-mode optical fiber, and its output end is connected to a computer through a data line, and is used to transmit the spectral wavelength signal of the first fiber Bragg grating sensor array. The computer analyzes the spectral wavelength signal and displays it as a temperature field and a stress field.

4. The water electrolysis cell status in-situ monitoring system according to claim 1, characterized in that: The second fiber Bragg grating sensor array comprises m tilted fiber Bragg grating sensors, each tilted fiber Bragg grating sensor has a tilt angle of 4 to 40 degrees, a grating region length of 10 to 15 mm, and a central wavelength of 1545 to 1580 nm; Each tilted fiber Bragg grating sensor is arranged at a central position in the electrode plate flow channel.

5. The water electrolysis cell status in-situ monitoring system according to claim 4, characterized in that: The spectrometer is multi-channel, and its input end is connected to m tilted fiber Bragg grating sensors of the second fiber Bragg grating sensor array through a single-mode optical fiber, and its output end is connected to a computer through a data line for transmitting the optical power signal of the second fiber Bragg grating sensor array. The computer analyzes the optical power signal and displays it as bubble status information.

6. The water electrolysis cell status in-situ monitoring system according to claim 3, characterized in that: The surface of each tilted fiber Bragg grating is coated with 1 to 50 nm of graphene.

7. The water electrolysis cell status in-situ monitoring system according to claim 1, characterized in that: The electrochemical workstation provides the voltage-current required for the electrolytic cell to work by leading out the positive electrode, the negative electrode and the reference electrode, and is connected to the computer through a data line, and the reaction rate is controlled by setting different voltage-currents by the computer.

8. The water electrolysis cell status in-situ monitoring system according to claim 1, characterized in that: The size of the flow channel inside the plate of the electrolytic cell ranges from 20 mm×20 mm to 100 mm×100 mm, and the electrolyte used in the water electrolytic cell is an alkaline solution or an acidic solution; The first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array are arranged on the pole plate in a serpentine shape along the flow channel inside the pole plate.

9. The water electrolysis cell status in-situ monitoring system according to claim 1, characterized in that: The light source is a broadband light source with a wavelength range of 1300-1600nm.

10. A method for in-situ monitoring of water electrolysis cell status, characterized in that: The steps include: S1, turning on the electrochemical workstation, providing the current-voltage required by the electrolytic cell, and starting the electrolytic cell to work; during the operation of the electrolytic cell, the temperature of the electrode plate rises, and bubbles are generated in the flow channel inside the electrode plate, and the bubbles flow in the flow channel with the electrolyte and pass through the second fiber Bragg grating sensor array; S2. Turn on the light source, which emits a signal light with a wavelength range of 1300-1600nm transmitted through a single-mode optical fiber to the first fiber Bragg grating sensor array and the second fiber Bragg grating sensor array; S3. The fiber Bragg gratings in the first fiber Bragg grating sensor array sequentially transmit the specific wavelength signal light transmitted by the light source to the demodulator; S4. The demodulator transmits the specific wavelength signal to the computer. Based on the principle that the spectral wavelength signal corresponds to the temperature, the computer processes the spectral wavelength signal and resolves the optical signal obtained by the first fiber Bragg grating sensor array into temperature information and stress information, thereby realizing in-situ monitoring of the temperature field and stress field state inside the water electrolysis cell; S5. The tilted fiber Bragg grating in the second fiber Bragg grating sensor array sequentially transmits the optical signal transmitted by the light source to the spectrometer; S6. The spectrometer transmits the optical power signal to the computer. Based on the principle that the optical power signal corresponds to the bubble state, the computer processes the optical power signal into a change in the refractive index of the gas-liquid two phases in the electrolyte in the electrolytic cell, thereby realizing in-situ monitoring of the bubble state generated in the electrolytic cell.

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