Sensing system suitable for series-parallel hydrogen production system and electrolytic bath in-situ diagnosis method

Abstract

The invention discloses a sensing system suitable for a series-parallel hydrogen production system and an electrolytic bath in-situ diagnosis method, and the sensing system comprises a light source which is used for emitting light; a demodulator; the conduction optical fiber is connected with the light source and is used for conducting light emitted by the light source; wherein the conduction optical fiber comprises a conduction section and a plurality of detection sections; the plurality of conduction sections are connected among the plurality of detection sections; a detection grating is arranged in the detection section, and part of light conducted along the conduction optical fiber is reflected by the detection grating; and the demodulator is also connected with the conductive optical fiber. Multi-point and multi-parameter detection is carried out through the arranged sensing system, the overall structure is simplified, and the instrument cost is reduced; besides, the sensing system provided by the embodiment of the invention performs signal transmission through the optical fiber, the problem of distortion or data loss caused by external interference is not easy to occur, and the safety of the system is improved in unattended hydrogen production scenes such as remote mountainous areas and islands.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis, and in particular to a sensor system and an electrolyzer in-situ diagnosis method applicable to a hybrid hydrogen production system. Background Art

[0002] During the electrolytic hydrogen production process, multiple physical parameters need to be monitored, such as temperature, pressure, flow, liquid level, and gas concentration. In addition to material and processing costs, instrumentation also accounts for a large proportion of the entire hydrogen production system. At the same time, the anti-interference ability of the instrumentation, as well as the fast and reliable signal transmission capability, are also the guarantee for the safe operation of the hydrogen production system.

[0003] The current solution is to use multiple independent sensors to detect physical quantities such as temperature and pressure, and finally integrate various types of data and transmit them to the control software. The hardware cost and installation and debugging cost of the instrument are high; and in application scenarios such as offshore wind power hydrogen production with electromagnetic interference, poor signals, and unattended operation, traditional electronic instruments are easily interfered with, resulting in sensor failure. The method of relying on the network for signal transmission cannot promptly feedback fault signals, posing a safety hazard. Summary of the invention

[0004] In view of this, the purpose of this application is to provide a sensor system and an electrolyzer in-situ diagnosis method suitable for a hybrid hydrogen production system, which is used to solve the technical problems in the prior art that the sensor system has a complex structure, high cost, and is easily affected by interference and causes errors.

[0005] In order to achieve at least one of the above purposes, the present application provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a sensor system suitable for a hybrid hydrogen production system, comprising:

[0007] A light source for emitting light;

[0008] A demodulator, for receiving light and demodulating the received light;

[0009] A transmission optical fiber is connected to the light source to transmit the light emitted by the light source; wherein,

[0010] The transmission optical fiber includes a transmission section and a detection section. There are multiple detection sections, which are respectively placed at multiple different detection points in the hydrogen production system.

[0011] The transmission segments are also provided in plurality and connected between the plurality of detection segments, so that the transmission optical fiber forms an optical channel;

[0012] A detection grating is provided in the detection section, and part of the light transmitted along the transmission optical fiber is reflected by the detection grating, and part of the light penetrates the detection grating;

[0013] The demodulator is also connected to the transmission optical fiber, and receives and demodulates the light reflected by the detection grating;

[0014] The detection grating is deformed under the action of temperature and / or pressure, thereby changing the characteristics of the light in the reflection part.

[0015] In some embodiments, a trigger component is further included, and the trigger component is arranged corresponding to the detection grating;

[0016] The trigger component is configured to respond to parameter changes other than temperature and / or pressure, convert the parameter changes other than temperature and / or pressure into temperature and / or pressure changes, and apply the temperature and / or pressure to the corresponding detection grating.

[0017] In some embodiments, a reference grating is further provided on the detection segment, and the reference grating has the same structure as the detection grating;

[0018] The reference grating is separated from the trigger component.

[0019] In some embodiments, the trigger component is a reactant coated on the detection segment at a position corresponding to the detection grating;

[0020] The reactant reacts with a specific type of substance to be detected and produces different degrees of temperature change and / or shape change in response to different concentrations of the substance to be detected;

[0021] The reactant acts on the corresponding detection grating to deform the detection grating.

[0022] In some embodiments, one side of the trigger component is connected to the environment to be detected, and the other side is in contact with the detection section at a position corresponding to the detection grating;

[0023] The trigger component is driven by the pressure of the environment to be detected to displace relative to the detection section, and applies a load to the detection section.

[0024] In some embodiments, a protective shell is further included, and the protective shell covers the outside of the detection section.

[0025] In some embodiments, a protective sleeve is further included, the protective sleeve being located inside the protective shell and connected to the protective shell;

[0026] The detection section is arranged inside the protective sleeve.

[0027] In a second aspect, the present application also provides an electrolytic cell in-situ diagnosis method, comprising the following steps:

[0028] Obtaining the real-time concentration of hydrogen in oxygen, and comparing it with the set concentration of hydrogen in oxygen. If the real-time concentration is consistent with the concentration, it is determined to be normal; if it is inconsistent with the concentration, it is determined to be abnormal;

[0029] After the abnormality occurs, determining whether the operating condition deviates, and if the operating condition deviates, making adjustments based on the sensing parameters to restore the operating condition to normal;

[0030] If there is no deviation in the operating conditions, diagnose the electrolyzer;

[0031] Wherein, the real-time concentration of hydrogen in oxygen and the sensing parameters are detected and acquired by the sensing system described in any one of the above items.

[0032] In some embodiments, diagnosing the electrolytic cell comprises:

[0033] Obtaining the current density i, the partial pressure P of hydrogen on the cathode side, and the flux N of permeated hydrogen;

[0034] The diffusion permeability coefficient D of the diaphragm and the mass transfer coefficient K of the catalytic layer satisfy the following relationship:

[0035]

[0036] According to the detected values ​​of i, P and N, the fitting values ​​of D and K are obtained;

[0037] Compare the obtained fitting values ​​of D and K with the corresponding standard values ​​to determine whether the corresponding diaphragm and catalyst layer have defects;

[0038] Where S is the solubility of hydrogen in water, C is the saturation concentration of hydrogen, and δ is the thickness of the diaphragm.

[0039] In some embodiments, comparing the obtained fitting values ​​of D and K with corresponding standard values ​​to determine whether the corresponding diaphragm and catalyst layer have defects includes:

[0040] If the fitting values ​​of D and K are consistent with the corresponding standard values, it is determined that there is no defect;

[0041] If the fitting value of D is larger than the corresponding standard value, it is determined that the diaphragm has a defect of perforation or small thickness;

[0042] If the fitting value of K is larger than the corresponding standard value, it is determined that the catalyst layer has a structural defect.

[0043] In some embodiments, when the operating condition deviates, adjustment is made based on the sensing parameters to restore the operating condition to normal, specifically:

[0044] Obtaining real-time detection values ​​of various parameters at corresponding positions of the hydrogen production system;

[0045] Comparing the real-time detected value of each parameter with the set range value corresponding to each parameter;

[0046] When the real-time detection value deviates from the corresponding set range value, the power of the control component of the corresponding parameter of the hydrogen production system is adjusted until the real-time detection value of the corresponding parameter is within the corresponding set range value.

[0047] In the above technical solution, a sensor system is set up to detect multiple points and multiple parameters of the hydrogen production system. Compared with the method of using multiple sensors for detection separately in the prior art, the overall structure is simplified, the instrument cost is reduced, and it is more convenient to debug the system as a whole; in addition, the sensor system provided in the embodiment of the present application performs signal transmission, which is not easily affected by external interference and causes distortion or data loss, thereby improving the accuracy of information transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0049] Figure 1 A schematic diagram of a sensing system provided in some embodiments of the present application for detecting various points and parameters of a hydrogen production system;

[0050] Figure 2 A schematic diagram of the structure of a sensor system provided in some embodiments of the present application;

[0051] Figure 3 A schematic diagram of the structure of a detection section provided in some embodiments of the present application;

[0052] Figure 4 A schematic diagram of the structure of a detection section for performing pressure detection provided in some embodiments of the present application;

[0053] Figure 5 A schematic diagram of a liquid level detection structure provided in some embodiments of the present application;

[0054] Figure 6 A schematic diagram of the structure of a detection section for performing pressure detection provided in some other embodiments of the present application;

[0055] Figure 7 A schematic diagram of the structure of a transmission optical fiber and a protective cover provided in some embodiments of the present application;

[0056] Figure 8 A schematic diagram of the structure of a detection section for flow detection provided in some embodiments of the present application;

[0057] Fig. 9 A schematic diagram of process nodes of a diagnostic method provided in some embodiments of the present application;

[0058] Fig.10 A schematic diagram of the relative relationship between the experimental value and the fitting value of the diffusion coefficient of the membrane provided in some embodiments of the present application at different temperatures;

[0059] Fig.11 A schematic diagram of the relative relationship between the experimental value and the fitted value of the mass transfer coefficient of the diffusion layer provided in some embodiments of the present application at different temperatures.

[0060] The reference numerals are as follows:

[0061] 1. Light source;

[0062] 2. Demodulator;

[0063] 3. transmission optical fiber, 31. transmission section, 32. detection section, 33. detection grating, 34. reference grating;

[0064] 4. Circulator;

[0065] 5. Trigger components;

[0066] 6. Protective shell;

[0067] 7. Protective cover. DETAILED DESCRIPTION

[0068] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0069] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions.

[0070] The "embodiment" mentioned in this application means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0071] The special word "exemplary" mentioned in this application means "used as an example, embodiment or illustrative". Any embodiment described as "exemplary" is not necessarily interpreted as being superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0072] In the description of this application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary and secondary relationship of the indicated technical features.

[0073] In the description of this application, the technical term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0074] In the description of the present application, the orientations or positional relationships indicated by technical terms such as "upper", "lower", "inside", "outside", "front", "back", "left", "right", "top", and "bottom" are orientations or positional relationships based on the working state of the present application. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0075] In the description of this application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0076] In the description of the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0077] In the description of the present application, “plurality” means two or more (including two), unless otherwise clearly and specifically defined.

[0078] In the description of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0079] As part of the creative concept of the present application, before describing the embodiments of the present application, it is necessary to analyze the causes of the problems of high cost and susceptibility to interference in the detection accuracy of multi-parameter detection of hydrogen production systems in related technologies, and obtain the technical solution of the embodiments of the present application through reasonable analysis.

[0080] In the related art, various parameters of the hydrogen production system are detected, and generally multiple sensors are used for separate detection. The detection information is transmitted to the central control system for corresponding data processing, and the working status of the hydrogen production system is detected based on the collected data. Temperature sensors, pressure sensors, flow sensors, etc. are installed at multiple points that need to be detected. The cost of the sensors themselves is relatively high, and the cost of installing and debugging multiple sensors, as well as the cost of subsequent maintenance are also high.

[0081] In some special places, such as offshore power generation and hydrogen production, the detected information needs to be transmitted over long distances. However, in the traditional way, the sensor collects the corresponding parameter information and transmits the data through the network. The signal is easily interfered, resulting in distortion of the detected information.

[0082] To this end, the present application provides a sensor system and an electrolyzer in-situ diagnosis method suitable for a hybrid hydrogen production system, thereby solving the technical problems in the prior art of high cost, easy interference of transmission signals, and resulting in erroneous detection information.

[0083] The technical solutions of the embodiments of the present application are described in detail below in conjunction with the accompanying drawings. The technical features involved in the different implementation modes of the present application described below can be combined with each other as long as there is no conflict between them.

[0084] To facilitate the description of the following embodiments, the present application takes the application of the sensor system to a hybrid hydrogen production system, and the electrolyzer diagnostic method is described by taking the PEM electrolyzer as an example; in other embodiments, the above-mentioned sensor system and diagnostic method can also be applied to other hydrogen production systems and electrolyzer structures, or other structures that require relevant physical quantity detection, by adaptively modifying the relevant structures to adapt them to the objects to which they are applied.

[0085] In an embodiment of the present application, a sensing system suitable for a hybrid hydrogen production system is provided, referred to as a "sensing system" for short; the sensing system is applied to the hybrid hydrogen production system to detect physical quantities such as temperature, pressure, flow, gas concentration, etc. at different points, so as to determine the working condition of the hydrogen production system accordingly. Figure 1 The example shows the detection of different parameters at different points in the hydrogen production system, including temperature, pressure, flow, liquid level, humidity, and gas. However, it should be noted that the embodiments of the present application only show some of the points by way of example, and other positions or different parameters at corresponding positions can also be detected in actual applications.

[0086] The sensing system adopts an optical fiber structure, with grating structures set at different positions on the entire optical fiber. When light is transmitted in the optical fiber and passes through the grating structure, the grating will partially reflect the passing light; when different temperatures or pressures act on the grating, the grating will produce a certain amount of deformation, which will then cause the properties of the reflected light to change, including the wavelength and phase of the reflected light.

[0087] The light reflected from the grating is received and demodulated. According to the correspondence between the wavelength of the light and the shape of the grating, the deformation amount produced by the corresponding grating can be obtained. Then, the value of the temperature or pressure acting on the grating to cause the deformation is determined through the deformation amount, thereby realizing the detection of temperature and pressure. As for parameters such as flow rate and gas concentration, relevant corresponding structures can be set to convert them into temperature or pressure acting on the grating to cause deformation, thereby realizing the detection of corresponding parameters, as shown below.

[0088] refer to Figure 2 The sensing system includes a light source 1, a demodulator 2 and a transmission optical fiber 3. The light source 1 is used to emit light, and the demodulator 2 is used to receive light and demodulate the received light. The transmission optical fiber 3 includes a transmission segment 31 and a detection segment 32. There are multiple transmission segments 31 and detection segments 32. The multiple detection segments 32 are distributed at multiple detection points. The multiple transmission segments 31 are connected between the multiple detection segments 32, so that the transmission optical fiber 3 forms an optical channel. It should be noted that the transmission optical fiber 3 can be set as an integrated structure, and the transmission segment 31 and the detection segment 32 are different sections of the transmission optical fiber 3; it can also be set as the transmission segment 31 and the detection segment 32 are separate independent optical fibers, which are connected to form a transmission optical fiber.

[0089] Among them, a detection grating 33 is provided in the detection section 32, and the detection grating 33 reflects the light transmitted through it. Part of the light is reflected by the detection grating 33, and part of the light continues to be transmitted along the transmission optical fiber 3 after penetrating the detection grating 33; the reflected light is transmitted along the transmission optical fiber 3 to the demodulator 2 for demodulation.

[0090] The light source 1, the demodulator 2 and the transmission optical fiber 3 are connected through a circulator 4. The circulator 4 has at least three ports. The light source 1, the demodulator 2 and the transmission optical fiber 3 are connected to the first port, the second port and the third port respectively. The circulator 4 is used to transmit light in a specific port sequence. The light input from the first port is output from the second port, and the light input from the second port is output from the third port. The light emitted by the light source 1 is transmitted along the transmission optical fiber 3 through the circulator 4, and the light reflected by the detection grating 33 is transmitted to the demodulator 4 for demodulation.

[0091] When light enters the detection grating 33, Bragg reflection occurs. When the grating period and effective refractive index of the detection grating 33 are determined, the central wavelength of the reflected light can be determined. Under the influence of external temperature and pressure, the grating period and effective refractive index of the detection grating 33 will change, that is, the central wavelength of the reflected light will change accordingly. In this way, according to the characteristics of the detection grating 33 itself, the change amount of the corresponding detection grating 33 when the wavelength of the reflected light changes can be determined, thereby determining the value of the temperature and pressure acting on the detection grating 33.

[0092] It should be noted that the changes in the detection grating 33 are not only reflected in the change in the wavelength of the reflected light, but the intensity and phase of the reflected light will also produce corresponding changes. In the embodiment of the present application, only the reflected light is demodulated to determine the change in the detection grating 33 through the wavelength change. In other embodiments, the change in the detection grating 33 can also be determined by analyzing the intensity and phase change of the reflected light, or by combining multiple characteristics for analysis, which will not be discussed one by one in the embodiment of the present application.

[0093] In the hydrogen production system, it is necessary to monitor the changes of multiple positions and multiple parameters, which can be achieved by using a conductive optical fiber 3. The conductive optical fiber 3 is arranged along multiple detection points. Light is transmitted along the conductive optical fiber 3. When passing through each detection grating 33, part of the light is reflected. The reflected light is transmitted to the demodulator 2. The demodulation analysis determines the change of the reflected light and the corresponding characteristic change of the detection grating 33, that is, the change of the grating period and the effective reflectivity. Only a single light source 1 and a demodulator 2 are needed to complete the corresponding work.

[0094] Compared with the existing technology, the method of setting up multiple sensors and installing them at multiple detection points effectively reduces the hardware cost of instruments and meters; optimizes the system structure, and is more convenient in installation and debugging, data collection, and instrument maintenance. In addition, the long-distance signal transmission method based on optical fiber sensing has stronger anti-interference ability, and the long-distance signal transmission effect is better for related scenarios such as offshore wind power hydrogen production.

[0095] In actual use, the hydrogen production system not only needs to directly detect temperature and pressure information, but also needs to detect parameters such as flow rate and gas concentration; Figure 3 The sensing system also includes a trigger component 5, which is arranged corresponding to the detection grating 33. The trigger component 33 is configured to respond to parameter changes other than temperature and / or pressure, convert the parameter changes other than temperature and / or pressure into temperature and / or pressure changes, and apply the above-mentioned converted temperature and / or pressure to the corresponding detection grating 33.

[0096] Specifically, fluid, gas, and moisture act on the trigger component 5, and are converted into a certain temperature and / or pressure through the action of the trigger component 5. In this way, the trigger component 5 can act on the detection grating 33 in the form of temperature and / or pressure, such as flow rate, gas concentration, and humidity. In this way, when the flow rate, gas concentration, and humidity change, the temperature and / or pressure acting on the detection grating 33 changes, and the grating period and effective reflectivity of the detection grating 33 are changed, and the wavelength of the reflected light changes accordingly, thereby realizing the detection of multiple parameters.

[0097] It should be noted that the trigger component 5 not only converts the change of parameters other than temperature and pressure into the change of temperature and / or pressure, but also can convert temperature into pressure, or convert pressure into temperature, or transmit pressure or change the direction of pressure. Of course, in actual use, in order to simplify the structure, reduce costs, ensure stable operation and other factors, when detecting temperature and pressure, it is sufficient to let the temperature and pressure directly act on the corresponding detection grating 33, that is, when detecting temperature and pressure, it is possible to choose whether to set the corresponding trigger component 5 according to actual needs.

[0098] Exemplary, reference Figure 3 The trigger component 5 is a reactant coated on the detection section 32 and at a position corresponding to the detection grating 33. The reactant reacts with a specific type of substance to be detected and produces different degrees of temperature change and / or shape change in response to changes in the amount of the substance to be detected. The temperature change and / or shape change then acts on the corresponding detection grating 33, causing the performance of the detection grating 33 to change accordingly.

[0099] Specifically, the reactant is a gas sensitive coating, and a gas sensitive material is deposited on the surface of the detection section 32. Among them, gas sensitive materials such as platinum and palladium can be used to detect the concentration of hydrogen in oxygen. Platinum and palladium absorb hydrogen or react with hydrogen to cause changes in temperature and shape. The temperature change acts on the detection grating 33, or the shape change applies different pressures to the detection grating 33, which will cause the properties of the detection grating 33 itself, thereby judging the corresponding gas concentration, pressure and other information.

[0100] In another embodiment, the trigger component 5 is a high molecular polymer film deposited on the periphery of the detection section 32. When the humidity in the environment changes, the high molecular polymer film will swell or shrink accordingly. The resulting stress change acts on the corresponding detection grating 33, changing the characteristics of the detection grating 33, and is reflected in the change in the properties of the reflected light, thereby realizing the detection of humidity.

[0101] That is, the reactants arranged on the detection section 32 interact with the substance to be detected, and under the action of physical and / or chemical changes, temperature changes and stress changes are generated to act on the detection grating 33, and the value of the parameter to be detected is determined by detecting the corresponding changes in the reflected light.

[0102] refer to Figure 4 The sensing system is also provided with a protective shell 6, which is covered on the outside of the detection section 32. On the one hand, it can provide a good protection for the detection section 32. On the other hand, when detecting pressure, by providing the protective shell 6, it is more convenient to install the trigger component 5 and keep the force applied by the trigger component 5 to the detection grating 33 stable.

[0103] Specifically, the protective shell 6 is a sleeve structure made of metal material, the transmission optical fiber 3 passes through the protective shell 6, and the detection section 32 is located in the protective shell 6. The trigger component 5 is connected to the protective shell 6, and at least part of it can be displaced relative to the protective shell 6, that is, the trigger component 5 is set to be slidingly connected with the protective shell 6, and slides relative to the protective shell 6 under pressure, or the trigger component 5 can be set to be deformable, deform under pressure, and apply force to the detection grating 33. One side of the trigger component 5 is connected to the environment to be detected, and the other side is abutted against the detection section 32 at the corresponding position of the detection grating 33.

[0104] Driven by the above-mentioned pressure of the environment to be detected, the trigger component 5 can partially displace relative to the protective shell 6, that is, relative to the detection segment 32. When the pressure of the environment to be detected is different, the magnitude of the load applied by the trigger component 5 to the detection segment 32 and the detection grating 33 is also different, which in turn affects the characteristics of the reflected light. By demodulating and analyzing the reflected light, the magnitude of the corresponding pressure can be determined.

[0105] For example, reference Figure 4 The trigger component 5 is a metal diaphragm. The pressure of the environment to be detected acts on the metal diaphragm, causing the metal diaphragm to deform. The deformed part of the metal diaphragm is fixedly connected to a side facing the detection section 32 with an abutting protrusion. In the initial state, the abutting protrusion is kept in contact with the detection section 32. When the metal diaphragm is subjected to external pressure, the metal diaphragm is deformed, and the abutting protrusion squeezes the detection section 32, causing the corresponding detection grating 33 to deform.

[0106] refer to Figure 5, shows a schematic diagram of using the sensing system to detect liquid level, the protective shell 6 is fixedly connected to the bottom of the corresponding container, the side of the metal diaphragm facing away from the detection grating 33 is connected to the inside of the container, the liquid in the container contacts the metal diaphragm, and the stress generated by the pressure acts on the metal diaphragm, causing the metal diaphragm to deform; the rise and fall of the liquid level in the container will cause the pressure at the metal diaphragm to change, and then change the deformation of the metal diaphragm and the pressure acting on the metal diaphragm, the detection grating 33 is deformed, and the liquid level is detected.

[0107] Figure 4 Only one load application method is exemplarily shown in FIG. 1 . In other embodiments, the load can be applied to the detection grating in different directions. For example, referring to Figure 6 , the load is applied to the detection grating 33 along the radial direction of the transmission optical fiber 3.

[0108] Furthermore, in order to avoid the problem that the applied pressure load may damage the detection grating 33 or the transmission optical fiber 3, refer to Figure 4 and Figure 6 When performing pressure detection, the corresponding detection section 32 is covered with a protective cover 7. For example, the protective cover 7 is made of a flexible polymer material. On the one hand, it ensures that the load is smoothly transmitted to the detection grating 33. On the other hand, it can provide good protection for the optical fiber 3. In actual use, the protective cover 7 is connected to the protective shell 6, so that the position of the conductive optical fiber 3 relative to the protective shell 6 can be more conveniently limited, which is convenient for the layout of the conductive optical fiber 3.

[0109] refer to Figure 7 , exemplarily showing a layout structure of a conductive optical fiber 3, through the provision of a protective cover 7, it can assist in fixing the position of the conductive optical fiber 3, and when detecting pressure, it can improve the stability of the pressure applied to the corresponding detection grating 33.

[0110] refer to Figure 8 When the sensor system detects flow, the trigger component 5 is fixedly connected to the protective cover 7, and the trigger component 5 is divided into a force-bearing part and a connecting part, wherein the connecting part is fixedly connected to the protective cover 7, and the cross-sectional area of ​​the force-bearing part perpendicular to the fluid flow direction is larger than the cross-sectional area of ​​the connecting part perpendicular to the fluid flow direction, which can detect the flow size more accurately and be more sensitive to small changes. In other embodiments, the flow direction of the fluid can also be set to be perpendicular to the extension direction of the detection section 32.

[0111] refer to Figure 3, the detection section 32 is also provided with a reference grating 34 corresponding to the detection grating 33. The reference grating 34 has the same structure as the detection grating 33, and the reference grating 34 is kept separated from the trigger component. When detecting parameters such as pressure, flow, hydrogen concentration in oxygen, and humidity, the detection grating 34 is not only affected by the state applied by the trigger component 5, but also by the temperature of the environment, which will affect the accuracy of the detection result of the detection grating 34 and cause errors; through the setting of the reference grating 34, the reflected light of the detection grating 33 and the corresponding reflected light of the reference grating 34 are combined and analyzed, and the changes in the reflected light of the detection grating 33 caused by factors other than the parameters to be detected can be removed, and the proportion of the changes caused by the effect of the parameters to be detected can be obtained, which can eliminate the influence of other irrelevant factors in the environment and improve the accuracy of the detection results.

[0112] In the case where the protective cover 7 is provided, the reference grating 34 should also be arranged inside the protective cover 7 to maintain consistency with the environment of the corresponding detection grating 33 .

[0113] In addition, the present application also provides an electrolytic cell in-situ diagnosis method, which is implemented based on the above-mentioned sensor system, referring to Fig. 9 , is a real-time process node diagram of the above method, specifically, including the following steps.

[0114] First, by using the above-mentioned sensing system, the hydrogen production system is tested for parameters, the real-time concentration of hydrogen in oxygen is obtained, and the real-time concentration of hydrogen in oxygen is compared with the set concentration of hydrogen in oxygen. If the real-time concentration is consistent with the above concentration, it is determined to be normal; if the real-time concentration is inconsistent with the above concentration, it is determined to be abnormal. Among them, the hydrogen concentration in oxygen is set as the factory value of the equipment, which can be determined according to the corresponding standard of the hydrogen production system. The specific determination method is well known to technicians in the relevant field and will not be repeated in this application.

[0115] If the result is normal, it means that the hydrogen production system is operating normally and no subsequent adjustment or testing steps are required.

[0116] When the above-mentioned abnormal situation occurs, it is necessary to determine whether the operating conditions of the hydrogen production system deviate. If there is a deviation in the operating conditions, adjustments are made based on the sensing parameters obtained by the above-mentioned sensing system until the operating conditions return to normal. If there is no deviation in the operating conditions, there is a risk of structural failure or damage to the electrolyzer, and the electrolyzer needs to be diagnosed to determine whether there is a fault in the electrolyzer structure and the specific type of fault.

[0117] Among them, operating conditions specifically refer to operating parameters, such as whether the values ​​of temperature, pressure, flow, etc. are within the set normal operating range. Deviations in operating conditions may be caused by a variety of factors. For example, if the power of the cooling system is low, or if there is a failure in the cooling system or a blockage in the cooling pipe, the temperature will rise abnormally; if there is a lack of necessary insulation measures, the temperature will be too low. Failure of the pressure regulating valve and abnormal operation of the hydrogen compressor will lead to problems with excessive system pressure; leakage of components and poor sealing of connection points will lead to problems with low system pressure.

[0118] Determine whether there is a deviation in the operating conditions, and when there is a deviation in the operating conditions, make adjustments based on the relevant parameters detected by the sensor system to restore the operating conditions to normal. The process needs to be implemented based on the corresponding parameters of the hydrogen production system detected by the above-mentioned sensor system. Specifically, the real-time detection values ​​of temperature, pressure, and flow at the corresponding position of the hydrogen production system are obtained through the sensor system. Of course, in other embodiments, relevant parameters such as humidity and gas concentration may also be included. In the embodiments of this application, only temperature, pressure, and flow are used as examples, and the application scenarios of the solution of this application are not limited thereto.

[0119] Afterwards, the real-time detection values ​​of temperature, pressure and flow rate are compared with the set range values ​​of temperature, pressure and flow rate. If the real-time detection values ​​are within the corresponding set range values, it indicates that the operating parameters have not deviated from the operating conditions; if the real-time detection values ​​deviate from the corresponding set range values, the power of the control components of the corresponding parameters of the hydrogen production system is adjusted until the real-time detection values ​​of the corresponding parameters are within the corresponding set range values.

[0120] For example, if the real-time detected value of the temperature is too high, the corresponding control component, that is, the working power of the cooling system, is adjusted to increase the cooling power and lower the temperature until the real-time detected value of the temperature is within the corresponding set range.

[0121] Of course, in actual operation, if the corresponding parameters have not returned to normal values ​​after adjusting the corresponding control components for a certain period of time, it is necessary to inspect the corresponding components to determine whether there is any structural damage to the components and perform corresponding maintenance work in a timely manner.

[0122] In addition, if there is no deviation from the above operating conditions, the electrolyzer needs to be diagnosed. Specifically, the changes in the corresponding parameters during the operation of the electrolyzer can reflect the working conditions of the corresponding components. Specifically, the electrolyzer includes a diaphragm and a catalyst layer. When the diaphragm and the catalyst layer are in a constant working environment, for example, when they are in a state of certain temperature and pressure, the diffusion coefficient D of the diaphragm and the mass transfer coefficient K of the catalyst layer are determined, that is, the properties of the diaphragm and the catalyst layer themselves are determined.

[0123] In this way, after obtaining the temperature and pressure parameter values, the amount of hydrogen permeated through the diaphragm and transmitted by the catalyst layer can be determined. If there is a deviation between the final flux N of hydrogen permeated through the diaphragm and the predetermined value, or there is a deviation between the hydrogen partial pressure P on the cathode side and the predetermined value, it indicates that the properties of the diaphragm or the catalyst layer itself have changed, that is, D and K have changed. Among them, N is determined by measuring the concentration of hydrogen in oxygen, and P is determined by measuring the hydrogen pressure on the cathode side. Of course, the above situation is determined when the working power of the electrolyzer is determined, or the working current density i is determined.

[0124] Most of the hydrogen produced at the cathode in the electrolyzer is discharged toward the outlet through the catalyst layer, and a small part permeates through the diaphragm to the anode. These two processes are related to the catalyst layer and the diaphragm material respectively. Most of the hydrogen that permeates through the diaphragm is transmitted in the form of dissolved hydrogen. This process can be described by Fick's diffusion law. Based on the above two points, the diffusion equation and mass conservation equation are established to satisfy the following relationship:

[0125]

[0126] Wherein, S is the solubility of hydrogen in water, P is the partial pressure of hydrogen on the cathode side, C is the saturation concentration of hydrogen, δ is the thickness of the diaphragm, and F is the Faraday constant.

[0127] In the actual working process, S, C, δ, and F in the above relationship are all determined values, N and P can be measured by the above sensor system, and the value of i is the set value of the hydrogen production system. In this way, the corresponding values ​​of N, P, and i in the hydrogen production process are obtained. According to the above relationship, the values ​​of the permeability coefficient D of the diaphragm and the mass transfer coefficient K of the catalytic layer can be fitted. According to the fitted values ​​of D and K, the standard values ​​of D and K (historical values ​​or equipment factory values) that the diaphragm and the catalytic layer should maintain in the corresponding working environment are compared to determine the information of the structure of the diaphragm and the catalytic layer, and judge whether the diaphragm and the catalytic layer are faulty, and the type of fault that exists based on the comparison information.

[0128] refer to Fig.10 , the trend of the permeability coefficient D of the diaphragm changing with temperature, including the value of the permeability coefficient D determined by experimental detection (i.e., the standard value), and the fitting value of the permeability coefficient D obtained by fitting the above relationship. It can be seen that the fitting value of the permeability coefficient D is basically the same as the actual value of the permeability coefficient D (i.e., the standard value).

[0129] In addition, refer to Fig.11, which shows the corresponding relationship between the mass transfer coefficient and temperature of the catalytic layer. Similarly, it includes the actual value of the mass transfer coefficient K determined by experiment (i.e., the standard value), and the fitting value of the mass transfer coefficient K obtained by fitting the above relationship. Similarly, the fitting value of the mass transfer coefficient K is basically the same as the actual value of the mass transfer coefficient K (i.e., the standard value).

[0130] As can be seen from the above, according to the fitting relationship provided in the embodiment of the present application, combined with the values ​​of the relevant parameters detected in real time, the fitting values ​​of the permeability coefficient D of the diaphragm and the mass transfer coefficient K of the catalytic layer can be accurately obtained, that is, the structural defects of the diaphragm and the catalytic layer can be accurately judged according to the obtained fitting values. In addition, the substantially same embodiment of the present application means that the two values ​​are the same, or the difference is within the allowable error range.

[0131] Based on the above-mentioned sensing system and the corresponding method, the values ​​of the permeability coefficient and the mass transfer coefficient can be determined more conveniently and accurately, which can assist in judging whether the corresponding diaphragm and the catalyst layer have faults, and timely perform maintenance and repairs.

[0132] In actual operation, the permeability coefficient D of the diaphragm and the mass transfer coefficient K of the catalyst layer are obtained by fitting according to the above method; then, the predetermined values ​​of D and K are determined according to the temperature value obtained by the above sensing system, and the structural information of the corresponding diaphragm and catalyst layer can be determined by comparison. If the value of D obtained by fitting is too large, it indicates that the thickness of the diaphragm is thinned (the permeation diaphragm resistance becomes smaller) or there are pinhole defects (the permeation channels become more and the interface size of the permeation channels becomes larger), wherein the thinning of the diaphragm thickness may be due to chemical attenuation or other reasons; if the value of K obtained by fitting is too small, it indicates that the structure of the catalyst layer is destroyed, and there are related types of faults such as the destruction of the hydrogen transmission channel. For the specific type of fault, after determining the mass transfer coefficient K of the catalyst layer, it can be determined according to the existing technology in the field.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A sensor system suitable for a hybrid hydrogen production system, characterized in that: include: A light source for emitting light; A demodulator, for receiving light and demodulating the received light; A transmission optical fiber is connected to the light source to transmit the light emitted by the light source; wherein, The transmission optical fiber includes a transmission section and a detection section. There are multiple detection sections, which are respectively placed at multiple different detection points in the hydrogen production system. The transmission segments are also provided in plurality and connected between the plurality of detection segments, so that the transmission optical fiber forms an optical channel; A detection grating is provided in the detection section, and part of the light transmitted along the transmission optical fiber is reflected by the detection grating, and part of the light penetrates the detection grating; The demodulator is also connected to the transmission optical fiber, and receives and demodulates the light reflected by the detection grating; The detection grating is deformed under the action of temperature and / or pressure, thereby changing the characteristics of the light in the reflection part.

2. The sensor system suitable for a hybrid hydrogen production system according to claim 1, characterized in that: It also includes a trigger component, and the trigger component is arranged corresponding to the detection grating; The trigger component is configured to respond to parameter changes other than temperature and / or pressure, convert the parameter changes other than temperature and / or pressure into temperature and / or pressure changes, and apply the temperature and / or pressure to the corresponding detection grating.

3. The sensor system suitable for a hybrid hydrogen production system according to claim 2, characterized in that: The detection section is also provided with a reference grating, and the reference grating has the same structure as the detection grating; The reference grating is separated from the trigger component.

4. The sensor system suitable for a hybrid hydrogen production system according to claim 2 or 3, characterized in that: The trigger component is a reactant coated on the detection section at a position corresponding to the detection grating; The reactant reacts with a specific type of substance to be detected and produces different degrees of temperature change and / or shape change in response to different concentrations of the substance to be detected; The reactant acts on the corresponding detection grating to deform the detection grating.

5. The sensor system suitable for a hybrid hydrogen production system according to claim 2 or 3, characterized in that: One side of the trigger component is connected to the environment to be detected, and the other side is in contact with the detection section at a position corresponding to the detection grating; The trigger component is driven by the pressure of the environment to be detected to displace relative to the detection section, and applies a load to the detection section.

6. The sensor system suitable for a hybrid hydrogen production system according to claim 5, characterized in that: It also includes a protective shell, which covers the outside of the detection section.

7. The sensor system suitable for a hybrid hydrogen production system according to claim 6, characterized in that: Also included is a protective sleeve, the protective sleeve is located inside the protective shell and connected to the protective shell; The detection section is arranged inside the protective sleeve.

8. An electrolytic cell in-situ diagnosis method, characterized in that: The following steps are involved: Obtaining the real-time concentration of hydrogen in oxygen, and comparing it with the set concentration of hydrogen in oxygen. If the real-time concentration is consistent with the concentration, it is determined to be normal; if it is inconsistent with the concentration, it is determined to be abnormal; After the abnormality occurs, determining whether the operating condition deviates, and if the operating condition deviates, making adjustments based on the sensing parameters to restore the operating condition to normal; If there is no deviation in the operating conditions, diagnose the electrolyzer; Wherein, the real-time concentration of hydrogen in oxygen and the sensing parameters are detected and acquired by the sensing system according to any one of claims 1-7.

9. The electrolytic cell in-situ diagnosis method according to claim 8, characterized in that: The diagnosing of the electrolytic cell comprises: Obtaining the current density i, the partial pressure P of hydrogen on the cathode side, and the flux N of permeated hydrogen; The diffusion permeability coefficient D of the diaphragm and the mass transfer coefficient K of the catalytic layer satisfy the following relationship: According to the detected values ​​of i, P and N, the fitting values ​​of D and K are obtained; Compare the obtained fitting values ​​of D and K with the corresponding standard values ​​to determine whether the corresponding diaphragm and catalyst layer have defects; Where S is the solubility of hydrogen in water, C is the saturation concentration of hydrogen, and δ is the thickness of the diaphragm.

10. The electrolytic cell in-situ diagnosis method according to claim 9, characterized in that: The step of comparing the obtained fitting values ​​of D and K with corresponding standard values ​​to determine whether the corresponding diaphragm and catalyst layer have defects includes: If the fitting values ​​of D and K are consistent with the corresponding standard values, it is determined that there is no defect; If the fitting value of D is larger than the corresponding standard value, it is determined that the diaphragm has a defect of perforation or thickness reduction; If the fitting value of K is smaller than the corresponding standard value, it is determined that the catalyst layer has a structural defect.

11. The electrolytic cell in-situ diagnosis method according to claim 8, characterized in that: When the operating condition deviates, adjustment is made based on the sensing parameters to restore the operating condition to normal, specifically: Obtaining real-time detection values ​​of various parameters at corresponding positions of the hydrogen production system; Comparing the real-time detected value of each parameter with the set range value corresponding to each parameter; When the real-time detection value deviates from the corresponding set range value, the power of the control component of the corresponding parameter of the hydrogen production system is adjusted until the real-time detection value of the corresponding parameter is within the corresponding set range value.

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