A method, system and apparatus for monitoring gas-liquid two-phase flow in an electrochemical reactor

Abstract

This application relates to the field of electrochemical technology and discloses a method, system, and device for monitoring gas-liquid two-phase flow in an electrochemical reactor. The method includes: acquiring first neutron imaging information of the flow channel region of the electrochemical reactor when the reactor is filled with electrolyte and not energized; acquiring second neutron imaging information of the flow channel region when the electrochemical reactor is energized; and generating gas-liquid two-phase distribution parameters in the flow channel region based on the first and second neutron imaging information. This solves the technical problem that related technologies cannot perform in-situ, non-invasive, and quantitative monitoring of gas-liquid two-phase flow inside an electrochemical reactor.

Description

Technical Field

[0001] This application relates to the field of electrochemical technology, and in particular to a method, system and equipment for monitoring gas-liquid two-phase flow in an electrochemical reactor. Background Technology

[0002] During operation, electrochemical reactors (such as electrolyzers and fuel cells) continuously release gas from the electrode surfaces, forming complex gas-liquid two-phase flows. Gas bubbles trapped within the flow channels can cause a "gas blockage" effect, significantly increasing system ohmic resistance, raising energy consumption, disrupting reactant transport, and potentially accelerating material corrosion. This is a core challenge limiting reactor efficiency and lifespan. Therefore, developing methods for in-situ, visual monitoring of the gas-liquid two-phase flow inside sealed metal reactors is crucial for flow channel optimization and performance improvement.

[0003] Currently, there is a lack of effective methods for in-situ, non-invasive, and visual monitoring of the gas-liquid two-phase flow inside a closed metal electrochemical reactor without damaging its structure. This technological gap severely restricts the research and optimization of high-performance electrochemical reactors. Summary of the Invention

[0004] This application provides a method, system, and equipment for monitoring gas-liquid two-phase flow in an electrochemical reactor, which solves the technical problem that related technologies cannot perform in-situ, non-invasive, and quantitative monitoring of gas-liquid two-phase flow inside an electrochemical reactor, and achieves the technical effect of non-destructive monitoring.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a method for monitoring gas-liquid two-phase flow in an electrochemical reactor. The method includes: acquiring first neutron imaging information of the flow channel region of the electrochemical reactor when the reactor is filled with electrolyte and not energized; acquiring second neutron imaging information of the flow channel region when the electrochemical reactor is energized; and generating gas-liquid two-phase distribution parameters in the flow channel region based on the first neutron imaging information and the second neutron imaging information.

[0006] The method for monitoring gas-liquid two-phase flow in an electrochemical reactor provided in this application quantifies the dynamic changes caused by bubbles by comparing the first neutron imaging information when no power is applied and the second neutron imaging information when power is applied, and converts them into gas-liquid two-phase distribution parameters. This enables in-situ, quantitative, and visual monitoring of gas-liquid two-phase flow inside a metal-sealed electrochemical reactor, providing data support for revealing the gas-liquid mass transfer mechanism in the flow channel and optimizing the reactor flow channel design.

[0007] Optionally, the gas-liquid two-phase distribution parameters include the gas layer thickness. Based on the first neutron imaging information and the second neutron imaging information, generating the gas-liquid two-phase distribution parameters in the flow channel region includes: converting the first neutron imaging information and the second neutron imaging information into a first neutron transmission intensity and a second neutron transmission intensity, respectively, based on a preset grayscale-neutron transmission intensity mapping relationship; and determining the gas layer thickness in the flow channel region based on the ratio of the first neutron transmission intensity to the second neutron transmission intensity.

[0008] By using a preset grayscale-neutron transmission intensity mapping relationship, neutron imaging information is converted into neutron transmission intensity. By calculating the ratio of the first neutron transmission intensity to the second neutron transmission intensity, the inherent background interference of the system, which is difficult to measure, such as the incident neutron intensity and the attenuation of the metal end plate of the electrochemical reactor, is cleverly eliminated, thus realizing in-situ, accurate, and quantifiable characterization of the gas-liquid two-phase distribution inside the metal-sealed electrochemical reactor.

[0009] Optionally, the second neutron imaging information is acquired through a periodic repetitive acquisition mode to capture the dynamic changes of the gas-liquid two-phase flow. The periodic repetitive acquisition mode is configured to acquire two neutron transmission images continuously with an exposure time of 30 seconds in each acquisition cycle, and the interval between adjacent acquisition cycles is 120 seconds.

[0010] By combining short-exposure (30-second) continuous shooting with long-interval (120-second) repetition, a balance was struck between image quality, dynamic resolution, and data reliability. Specifically, the 30-second exposure ensured that a single image had a sufficient signal-to-noise ratio for quantitative calculation, and the continuous acquisition of two images enabled on-site verification and averaging of instantaneous data. The 120-second interval allowed the capture of representative gas-liquid two-phase flow dynamic processes evolving on a minute-by-minute scale, such as the generation, transport, and discharge cycles of bubbles, thus comprehensively recording the temporal evolution of gas-liquid distribution within the flow channel under different operating conditions.

[0011] Optionally, the energized operation state is achieved by connecting the electrochemical reactor to a DC power supply to receive current, connecting it to a solution circulation pipeline to drive the electrolyte circulation, and connecting it to a gas collection pipeline to exhaust gas.

[0012] By connecting the electrochemical reactor to a DC power supply, solution circulation pipeline, and gas collection pipeline, a real electrochemical reaction environment is simulated, providing a safe, stable, and continuous experimental environment for in-situ, safe, and reliable dynamic monitoring of gas-liquid two-phase flow.

[0013] Optionally, the electrochemical reactor includes anion exchange membrane water electrolyzer, proton exchange membrane water electrolyzer, alkaline water electrolyzer, polymer electrolyte membrane fuel cell, solid oxide fuel cell, and alkaline fuel cell.

[0014] The method for monitoring gas-liquid two-phase flow in electrochemical reactors provided in this application has cross-system universality and unified quantitative analysis capability. It can overcome the differences in materials, structure and chemical environment of different electrolysis systems such as alkaline, acidic and polymer membranes, penetrate their common metal sealed structure, and realize in-situ, quantitative and visualized monitoring of internal gas-liquid two-phase flow under different operating modes (such as electrolytic cells and fuel cells). Thus, it provides a unified and standard research method for the optimization of flow channels and performance improvement of various electrochemical reactors, and expands its application scope.

[0015] Optionally, in the energized operating state, the current density in the electrochemical reactor ranges from 0 to 500 mA / cm². 2 The electrolyte flow rate ranges from 0 to 100 mL / min.

[0016] By systematically changing these two parameters, setting different operating conditions, and conducting observations, it is possible to systematically reveal the intrinsic laws and quantitative relationships of gas-liquid two-phase flow as a function of reaction intensity and hydrodynamics, providing comprehensive data support for optimizing flow channel design.

[0017] Optionally, the flow field type of the flow channel region includes, but is not limited to, parallel flow channels, needle-shaped flow channels, or serpentine flow channels.

[0018] The monitoring method for gas-liquid two-phase flow in an electrochemical reactor provided in this application is applicable to different flow field types. By analyzing the intrinsic influence of different flow field geometric layouts on the distribution of gas-liquid two-phase flow, bubble retention points, and discharge efficiency, it provides data support for optimizing various flow field designs.

[0019] Secondly, embodiments of this application provide a monitoring system for gas-liquid two-phase flow in an electrochemical reactor. The system includes: an electrochemical reactor; a neutron imager, used to acquire first neutron imaging information of the flow channel region of the electrochemical reactor when the reactor is filled with electrolyte and not energized; and to acquire second neutron imaging information of the flow channel region when the electrochemical reactor is energized; and a generation module, used to generate gas-liquid two-phase distribution parameters in the flow channel region based on the first neutron imaging information and the second neutron imaging information.

[0020] Thirdly, embodiments of this application provide a computer device, including: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the above-described method for monitoring gas-liquid two-phase flow in an electrochemical reactor.

[0021] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer instructions, which are used to cause a computer to execute the above-described method for monitoring gas-liquid two-phase flow in an electrochemical reactor.

[0022] Fifthly, embodiments of this application provide a computer program product, including computer instructions, which are used to cause a computer to execute the above-described method for monitoring gas-liquid two-phase flow in an electrochemical reactor. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating a method for monitoring gas-liquid two-phase flow in an electrochemical reactor, provided as an embodiment of this application; Figure 2 A schematic diagram of a serpentine flow channel provided in an embodiment of this application; Figure 3 This is a schematic diagram of the monitoring system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the first neutron imaging information provided in an embodiment of this application; Figure 5 This is a schematic diagram of the first neutron imaging information provided in an embodiment of this application; Figure 6 A pseudo-color image of gas-liquid distribution within a serpentine flow channel provided in an embodiment of this application; Figure 7 A schematic diagram of a needle-shaped flow channel provided in an embodiment of this application; Figure 8 A pseudo-color image of gas-liquid distribution within a needle-shaped flow channel provided in an embodiment of this application; Figure 9 A schematic diagram of a parallel flow channel provided in an embodiment of this application; Figure 10 A pseudo-color image of gas-liquid distribution in a parallel flow channel provided in an embodiment of this application; Figure 11 A schematic diagram of a monitoring system for gas-liquid two-phase flow in an electrochemical reactor provided for an embodiment of this application; Figure 12 A schematic diagram of a neutron imager provided in an embodiment of this application; Figure 13This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In electrochemical reactions and industrial electrosynthesis processes involving gas evolution, such as water electrolysis, carbon dioxide reduction, chlor-alkali industry, and aluminum electrolysis, bubble management within the reactor flow channel is a crucial core technical challenge. The continuous accumulation of trapped gas within the flow channel creates a "gas blockage" effect. In alkaline reactor systems, this blocks the conduction pathway of hydroxide ions; in proton exchange membrane reactors, it hinders the transmembrane migration of protons. This obstruction of ion conduction significantly increases the system's ohmic resistance, causing a simultaneous increase in reactor operating voltage and energy consumption, resulting in severe energy waste. Furthermore, gas retention can trigger a series of chain reactions and negative effects. On the one hand, it disrupts the uniform flow of the electrolyte or reaction medium, damaging the transport balance between reactants and products, leading to localized insufficient reactant supply and product accumulation on the electrode surface. In processes requiring high selectivity, such as carbon dioxide reduction, this problem can further increase side reactions and reduce the yield of the target product. On the other hand, abnormal local flow and concentration can exacerbate the corrosion and wear of electrode materials and may cause cavitation damage to the flow channel walls, ultimately accelerating the overall performance degradation of the reactor, shortening its service life, and increasing maintenance costs and downtime losses in industrial production. Therefore, developing a method to accurately and efficiently monitor the gas-liquid two-phase distribution and flow characteristics inside an electrochemical reactor is crucial for optimizing flow channel design, solving the gas retention problem, and improving reactor performance and efficiency. However, industrial-grade electrochemical reactors are mostly sealed metal structures to achieve functions such as pressure resistance, sealing, and conductivity, making in-situ visualization and monitoring of their internal processes extremely difficult.

[0027] Currently, commonly used bubble observation technologies in the industry mainly include: high-speed imaging, which, although possessing high frame rate imaging capabilities and able to directly capture the dynamic behavior of bubbles, has extremely poor penetration and cannot penetrate metal end plates such as titanium and nickel. It is only suitable for laboratory-scale reactors made of transparent materials such as acrylic and cannot be applied to metal-sealed equipment in actual industry; high-energy ray imaging (such as X-rays or gamma rays), which has strong penetration capabilities and can observe some non-transparent equipment. However, for thick metal end plates, extremely high doses of radiation are required for imaging, which not only leads to low image signal-to-noise ratio and blurred details, but also poses significant radiation safety risks. The equipment is also susceptible to radiation damage, making it difficult to adapt to in-situ monitoring scenarios that require long-term, safe operation; and indirect measurement methods such as electrochemical impedance spectroscopy. Although these methods are simple to operate, their observation is indirect. They can only infer bubble behavior through changes in electrical signals and cannot directly obtain key visual information such as bubble morphology, position, and spatial distribution, making them difficult to use for precise flow channel design and mechanism research.

[0028] In summary, there is a lack of effective methods for in-situ, non-invasive, and visual monitoring of the gas-liquid two-phase flow inside a closed metal electrochemical reactor without damaging the structure. This technological gap severely restricts the research and optimization of high-performance electrochemical reactors.

[0029] Neutron imaging technology, as an emerging non-destructive testing technology, offers potential solutions to the aforementioned problems due to its high sensitivity to light elements (such as hydrogen) and strong penetrating power to various metals. However, it has not yet been systematically applied to solve the specific technical problem of monitoring gas-liquid two-phase flow inside electrochemical reactors.

[0030] This application provides a method for monitoring gas-liquid two-phase flow in an electrochemical reactor. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for monitoring gas-liquid two-phase flow in an electrochemical reactor, as provided in this application embodiment, is shown below. Figure 1 As shown, the process includes the following steps: Step S1: With the electrochemical reactor filled with electrolyte and without power applied, acquire the first neutron imaging information of the flow channel region of the electrochemical reactor.

[0032] Neutron imaging information of the flow channel region can directly, in situ, and quantitatively characterize the gas-liquid two-phase flow within a closed electrochemical reactor. Neutron imaging information can be a neutron transmission image, specifically a pixel matrix containing grayscale values.

[0033] When the electrochemical reactor is filled with electrolyte and no power is applied, there are no bubbles in the flow channel region. The first neutron imaging information acquired at this time can be used as a reference. The changes in imaging information caused by bubbles generated during subsequent energized operation can be compared with this reference to quantify the gas-liquid distribution parameters.

[0034] Step S3: When the electrochemical reactor is in energized operation, acquire the second neutron imaging information of the flow channel region.

[0035] The energized operation state refers to the state in which the electrolyte of an electrochemical reactor is in a driven circulation state while it is connected to a DC power supply to carry out an electrolysis reaction, thereby continuously generating and maintaining a dynamic gas-liquid two-phase flow in its internal flow channels.

[0036] Step S5: Based on the first neutron imaging information and the second neutron imaging information, generate the gas-liquid two-phase distribution parameters in the flow channel region.

[0037] Because gas replaces liquid in the flow channel region, it causes a change in neutron penetration capability. By comparing the first and second neutron imaging information of the flow channel region, gas-liquid two-phase distribution parameters can be generated. These parameters are used to quantify the spatial occupancy and relative proportion of gas and liquid phases in the flow channel region. These parameters can include gas layer thickness, gas volume fraction, etc.

[0038] The method for monitoring gas-liquid two-phase flow in an electrochemical reactor provided in this application quantifies the dynamic changes caused by bubbles by comparing the first neutron imaging information when no power is applied and the second neutron imaging information when power is applied, and converts them into gas-liquid two-phase distribution parameters. This enables in-situ, quantitative, and visual monitoring of gas-liquid two-phase flow inside a metal-sealed electrochemical reactor, providing data support for revealing the gas-liquid mass transfer mechanism in the flow channel and optimizing the reactor flow channel design.

[0039] In some specific embodiments, the gas-liquid two-phase distribution parameters include the gas layer thickness. Based on the first neutron imaging information and the second neutron imaging information, generating the gas-liquid two-phase distribution parameters in the flow channel region includes: converting the first neutron imaging information and the second neutron imaging information into a first neutron transmission intensity and a second neutron transmission intensity, respectively, based on a preset grayscale-neutron transmission intensity mapping relationship; and determining the gas layer thickness in the flow channel region based on the ratio of the first neutron transmission intensity to the second neutron transmission intensity.

[0040] The gas layer thickness refers to the total attenuation caused by all bubbles along the neutron beam penetration path, equivalent to the attenuation produced by a continuous gas layer. The geometric thickness of this equivalent gas layer is called the gas layer thickness. The change in electrolyte thickness along the neutron beam penetration direction is numerically equal to the gas layer thickness. A pre-defined grayscale-neutron transmission intensity mapping relationship can be obtained through a pre-experiment calibration process. For example, a series of materials with known neutron attenuation characteristics are used; these materials are called "standard samples." These standard samples are sequentially placed in the neutron beam path and photographed using the same imaging detector to obtain neutron transmission images. Simultaneously, a highly precise neutron detector directly measures the actual neutron intensity after penetrating the samples. A standard curve is plotted with the actual neutron intensity measured by the detector as the x-axis and the average grayscale value of the image captured by the imaging detector as the y-axis. This standard curve can be used to characterize the pre-defined grayscale-neutron transmission intensity mapping relationship. In the formal experiment, the corresponding neutron transmission intensity can be deduced simply by capturing neutron transmission images and using the grayscale values ​​of the images and this pre-defined standard curve.

[0041] The thickness of the gas layer in the flow channel region can be determined based on the Lambert-Beer law of neutron decay and the ratio of the first neutron transmission intensity to the second neutron transmission intensity.

[0042] By using a preset grayscale-neutron transmission intensity mapping relationship, neutron imaging information is converted into neutron transmission intensity. By calculating the ratio of the first neutron transmission intensity to the second neutron transmission intensity, the inherent background interference of the system, which is difficult to measure, such as the incident neutron intensity and the attenuation of the metal end plate of the electrochemical reactor, is cleverly eliminated, thus realizing in-situ, accurate, and quantifiable characterization of the gas-liquid two-phase distribution inside the metal-sealed electrochemical reactor.

[0043] In some specific embodiments, the second neutron imaging information is acquired through a periodic repetitive acquisition mode to capture the dynamic changes of the gas-liquid two-phase flow. The periodic repetitive acquisition mode is configured to acquire two neutron transmission images continuously with an exposure time of 30 seconds in each acquisition cycle, and the interval between adjacent acquisition cycles is 120 seconds.

[0044] The periodic repetitive acquisition mode was adopted to overcome the limitations of neutron imaging, which suffers from long single exposures and difficulty in capturing rapid dynamic processes. A strategy combining short-exposure (30-second) continuous shooting with long intervals (120-second) repetition balanced image quality, dynamic resolution, and data reliability. Specifically, the 30-second exposure ensured a sufficient signal-to-noise ratio for quantitative calculations in a single image; continuous acquisition of two images enabled in-field verification and averaging of instantaneous data; and the 120-second interval allowed for capturing representative gas-liquid two-phase flow dynamic processes evolving on a minute-by-minute scale, such as the generation, transport, and discharge cycles of bubbles, thus comprehensively recording the temporal evolution of gas-liquid distribution within the flow channel under different operating conditions.

[0045] In some specific embodiments, the energized operation state is achieved by connecting the electrochemical reactor to a DC power supply to receive current, connecting it to a solution circulation pipeline to drive the electrolyte circulation, and connecting it to a gas collection pipeline to exhaust gas.

[0046] The solution circulation pipeline is used for the delivery, circulation, and replenishment of the electrolyte, providing a continuous and controlled liquid flow to the electrochemical reactor. The solution circulation pipeline mainly includes a peristaltic pump, a gas washing bottle, and hoses connecting various components. The peristaltic pump precisely controls the electrolyte flow rate. The gas collection pipeline is used for the emission and collection of gases generated by the electrochemical reactor, preventing gas accumulation within the system and ensuring the accuracy of observation data. The gas collection pipeline mainly consists of a gas collection bag and hoses connecting various components.

[0047] By connecting the electrochemical reactor to a DC power supply, solution circulation pipeline, and gas collection pipeline, a real electrochemical reaction environment is simulated, providing a safe, stable, and continuous experimental environment for in-situ, safe, and reliable dynamic monitoring of gas-liquid two-phase flow.

[0048] In some specific embodiments, the electrochemical reactor includes anion exchange membrane water electrolyzer (AEMWE), proton exchange membrane water electrolyzer (PEMWE), alkaline water electrolyzer (AWE), polymer electrolyte membrane fuel cell (PEMFC), solid oxide fuel cell (SOFC), and alkaline fuel cell (AFC), etc.

[0049] The method for monitoring gas-liquid two-phase flow in electrochemical reactors provided in this application has cross-system universality and unified quantitative analysis capability. It can overcome the differences in materials, structure and chemical environment of different electrolysis systems such as alkaline, acidic and polymer membranes, penetrate their common metal sealed structure, and realize in-situ, quantitative and visualized monitoring of internal gas-liquid two-phase flow under different operating modes (such as electrolytic cells and fuel cells). Thus, it provides a unified and standard research method for the optimization of flow channels and performance improvement of various electrochemical reactors, and expands its application scope.

[0050] In some specific embodiments, under the energized operating condition, the current density in the electrochemical reactor ranges from 0 to 500 mA / cm². 2 The electrolyte flow rate ranges from 0 to 100 mL / min.

[0051] Electrolyte flow rate characterizes the volume of electrolyte flowing through the flow channel of an electrochemical reactor per unit time. Current density determines the gas generation rate; a higher current density results in more bubbles being generated per unit time. Electrolyte flow rate determines the liquid's ability to flush and carry bubbles; a higher flow rate leads to stronger fluid shear force, making it easier to carry away bubbles and prevent their retention. By systematically changing these two parameters, setting different operating conditions, and conducting observations, the intrinsic laws and quantitative relationships of gas-liquid two-phase flow with reaction intensity and hydrodynamic variations can be systematically revealed, providing comprehensive data support for optimizing flow channel design.

[0052] In some specific embodiments, the flow field type of the flow channel region includes, but is not limited to, parallel flow channels, needle-shaped flow channels, or serpentine flow channels.

[0053] The flow field type in the channel region refers to the geometric layout of the grooves machined on the inner side of the metal endplate of an electrochemical reactor to guide the flow of electrolyte. For example, a parallel channel consists of multiple straight and parallel grooves. A serpentine channel is a long, continuous, and meandering groove. A needle-shaped channel consists of a series of densely arranged protrusions (such as cylinders or square pillars) or pits, forming a complex network of flow paths.

[0054] The monitoring method for gas-liquid two-phase flow in an electrochemical reactor provided in this application is applicable to different flow field types. By analyzing the intrinsic influence of different flow field geometric layouts on the distribution of gas-liquid two-phase flow, bubble retention points, and discharge efficiency, it provides data support for optimizing various flow field designs.

[0055] The following description is based on specific embodiments.

[0056] Example 1 This embodiment uses an anion exchange membrane water electrolyzer (AEMWE) as the test object. The AEMWE employs specially thinned titanium-based metal end plates with a serpentine flow field and a flow channel size of 50mm × 50mm. Please refer to [reference needed]. Figure 2 , Figure 2 This is a schematic diagram of the serpentine flow channel provided in an embodiment of this application. The electrolyte used in the experiment was a 0.1 mol / L KOH solution.

[0057] The monitoring method for gas-liquid two-phase flow in an electrochemical reactor specifically includes the following steps: Step 1: Set up the AEMWE monitoring system. Please refer to... Figure 3 , Figure 3 This is a schematic diagram of a monitoring system provided in an embodiment of this application. Figure 3 As shown, the electrolytic cell, solution circulation pipeline, and gas collection pipeline are sequentially connected via flexible hoses to form a closed electrolyte circulation loop. The gas collection pipeline is connected to the exhaust port of the solution circulation pipeline to collect hydrogen generated at the cathode and oxygen generated at the anode, respectively. The solution circulation pipeline consists of two 250mL three-necked gas washing bottles, two 100mL two-necked gas washing bottles, and flexible hoses. The gas collection pipeline includes two gas collection bags. The positive and negative terminals of the DC power supply are connected to the corresponding electrodes of the electrolytic cell. The computer controller establishes a communication connection with the peristaltic pump, DC power supply, and neutron imager to achieve automatic control of flow rate, current density, and data acquisition parameters.

[0058] Step 2: Sample Positioning and Parameter Setting. Fix the electrolytic cell onto the sample stage of the neutron imager and adjust its position to ensure the neutron beam penetrates the flow channel region perpendicularly and the entire flow channel is completely within the imaging field of view. Set the experimental parameters using the computer controller: current density adjustment range is 0-500 mA / cm², and electrolyte flow rate adjustment range is 0-100 mL / min.

[0059] Step 3, Pre-image capture and parameter optimization. Before applying the current, a neutron imaging pre-image is taken to confirm whether the electrolyzer position allows for complete imaging of the flow channel, and to optimize the data acquisition parameters. The final formal acquisition parameters are determined as follows: for each operating condition, a 30-second exposure time is used, with two images acquired consecutively each time, and this process is repeated after a 120-second interval.

[0060] Step 4: System preparation and operational condition verification. Prepare a 0.1 mol / L KOH electrolyte, inject it into the system, and start the peristaltic pump for circulation. Perform a pre-run on the electrolyzer to ensure that the system is well-sealed, leak-free, and operating stably.

[0061] Step 5, Background Image Acquisition. Under conditions of no applied current and the flow channel filled with electrolyte, the electrolytic cell is imaged using neutron imaging technology. The resulting image is recorded as the first neutron imaging information (i.e., the background image) and used for background subtraction in subsequent data processing. Please refer to [link / reference]. Figure 4 , Figure 4 This is a schematic diagram of the first neutron imaging information provided in an embodiment of this application. Figure 4 As shown, at this time, due to the strong attenuation of neutrons by the electrolyte, the flow channel appears as a dark area in the image.

[0062] Step Six: Operating Conditions and Dynamic Image Acquisition. The current density was controlled at 100 mA / cm², and the electrolyte flow rate was sequentially set to 10, 50, and 100 mL / min for the experiment. At each flow rate, the DC power supply and peristaltic pump were turned on to power on the AEMWE system, and the neutron detector was activated for imaging (acquisition time 30 seconds / frame). The computer controller synchronously recorded the electrolyzer voltage. Please refer to [reference needed]. Figure 5 , Figure 5 This is a schematic diagram of the first neutron imaging information provided in an embodiment of this application. Figure 5 As shown, in this state, the gas generated by the electrochemical reaction enters the flow channel. Since the gas's ability to attenuate neutrons is much weaker than that of the liquid electrolyte, areas with high gray values ​​in the image correspond to gas accumulation, while areas with low gray values ​​correspond to liquid filling.

[0063] Step 7: Image Processing and Quantitative Analysis. The computer controller automatically calls built-in algorithms and software (such as ImageJ and Matlab) to process and analyze the acquired sequence of images, including: using ImageJ software to uniformly adjust the brightness and contrast of the images, perform noise reduction, and normalize the grayscale (range 0-1) to enhance gas-liquid contrast. In Matlab software, the images are imported as a grayscale matrix, flat-field correction is performed, and the intensity values ​​of the regions are quantitatively extracted. Based on the calibration curve, the grayscale values ​​are converted into actual neutron intensities and substituted into the Lambert-Beer equation to calculate the gas layer thickness, finally drawing a pseudo-color map of the gas-liquid distribution under this condition.

[0064] The specific calculation process for the gas layer thickness is as follows: Before the experiment, a pre-defined grayscale-neutron transmission intensity mapping relationship was established using a standard sample with known attenuation characteristics and following the standard calibration procedure of the neutron imager. The average neutron intensity under the background state was then... Neutron intensity of each pixel under operating conditions Substituting into the derivation formula based on Lambert-Beer's law: In the above formula, This indicates the intensity of neutrons before they penetrate the electrochemical reactor. and These correspond to the neutron intensities after penetration into the electrochemical reactor under conditions of no electrochemical reaction and under conditions of gas generation during the reaction, respectively. and These represent the neutron attenuation coefficients of the electrolyte and the metal end plate, respectively. and These represent the thicknesses of the electrolyte and the metal end plate in the neutron penetration direction, respectively.

[0065] because As a constant value, it has no impact on the observation of the gas-liquid two-phase flow within the overall electrochemical reactor. In the embodiments of this application, dimensionless numbers are used. This parameter is considered as a whole and defined as the electrolyte decay variable. It can be used to indirectly quantify the change in electrolyte layer thickness, thereby indirectly quantifying the gas layer thickness. The calculation formula is as follows: Finally, the calculated spatial distribution data of the gas layer thickness under each operating condition were plotted into a pseudo-color map to visually demonstrate the gas-liquid two-phase distribution within the flow channel under specific operating conditions. Please refer to [reference needed]. Figure 6 , Figure 6 The pseudo-color image of gas-liquid distribution in the serpentine flow channel provided in the embodiments of this application is as follows: Figure 6 As shown, the corresponding operating parameters include a current density of 100 mA / cm² and a flow rate of 10 mL / min. Along the y-axis in the flow channel, the yellow area increases significantly, indicating that the gas accumulation phenomenon in the upper part of the flow channel is obvious. Along the x-axis, the color change in a single flow channel is gradual, indicating that the gas is distributed relatively evenly in a single flow channel.

[0066] Example 2 This embodiment aims to illustrate the universality of the gas-liquid two-phase flow monitoring method in the electrochemical reactor provided in this application for different flow field structures. The only difference from Embodiment 1 is that the metal end plate in the electrochemical reactor is a specially thinned titanium-based end plate with a needle-shaped flow field etched on it; the flow channel dimensions remain the same as in Embodiment 1. Please refer to [reference needed]. Figure 7 , Figure 7 This is a schematic diagram of the needle-shaped flow channel provided in an embodiment of this application. The specific experimental steps are exactly the same as those in Embodiment 1; please refer to [reference needed]. Figure 8 , Figure 8 The pseudo-color image of gas-liquid distribution in the needle-shaped flow channel provided in this application embodiment is generated by obtaining the gas-liquid two-phase distribution parameters of the needle-shaped flow channel under different operating conditions using the method described above. Figure 8 As shown.

[0067] Example 3 This embodiment aims to further illustrate the universality of the gas-liquid two-phase flow monitoring method in the electrochemical reactor provided in this application for different flow field structures. The only difference from Embodiment 1 is that the metal end plate in the electrochemical reactor is a specially thinned titanium-based end plate with parallel flow channels etched on it. The flow channel dimensions remain the same as in Embodiment 1. Please refer to [reference needed]. Figure 9 , Figure 9 This is a schematic diagram of a parallel flow channel provided in an embodiment of this application. The specific experimental steps are exactly the same as those in Embodiment 1. Using the described method, the gas-liquid two-phase distribution parameters of the parallel flow channel under different operating conditions are obtained, and a pseudo-color image is generated. Please refer to... Figure 10 , Figure 10 A pseudo-color image of gas-liquid distribution in a parallel flow channel provided for an embodiment of this application.

[0068] Accordingly, please refer to Figure 11 , Figure 11 A schematic diagram of a monitoring system for gas-liquid two-phase flow in an electrochemical reactor, as provided in an embodiment of this application, is shown below. Figure 11 As shown, the system includes: an electrochemical reactor; a neutron imager, used to acquire first neutron imaging information of the flow channel region of the electrochemical reactor when the reactor is filled with electrolyte and not energized; and to acquire second neutron imaging information of the flow channel region when the electrochemical reactor is energized; and a generation module, used to generate gas-liquid two-phase distribution parameters in the flow channel region based on the first neutron imaging information and the second neutron imaging information.

[0069] The generation module can specifically be a software algorithm within the computer controller. For example, the computer controller can automatically and continuously perform preliminary processing on the images captured by neutron imaging using ImageJ software under each set operating condition. This includes uniform adjustment of brightness and contrast, as well as noise reduction. Then, in Matlab software, the original image is imported as a grayscale matrix, and standard flat-field correction is performed. By analyzing the grayscale distribution of the corrected matrix, the intensity values ​​of the regions are quantitatively extracted, and a pseudo-color image is drawn for that operating condition. The metal endplates in the electrochemical reactor are specially thinned. Compared with neutron imaging using unthinned metal endplates, this significantly increases the number of neutron beams penetrating the metal endplates, enhancing the effectiveness of neutron imaging for observing gas-liquid two-phase flows.

[0070] The monitoring system also includes a solution circulation line and a gas collection line connected to the electrochemical reactor via hoses. The solution circulation line includes a peristaltic pump to control the input and output of the electrolyte flow rate in the electrochemical reactor, driving the electrolyte circulation. A DC power supply is connected to the electrodes of the electrochemical reactor to apply current density. A computer controller is also used to control the peristaltic pump and the DC power supply to regulate the electrolyte flow rate and current density. Please refer to [reference needed]. Figure 12 , Figure 12 This is a schematic diagram of a neutron imager provided in an embodiment of this application. Figure 12 As shown, the neutron imager 100 mainly includes a neutron source 101, a target station 102, a bandwidth chopper 103, a neutron conduit 104, and an imaging detector 105. The neutron source emits neutrons perpendicular to the axis of the neutron conduit, and the electrochemical reactor 200 is located on the neutron beam path to ensure complete imaging of the flow channel region.

[0071] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0072] In this embodiment, the monitoring system for the gas-liquid two-phase flow in the electrochemical reactor is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0073] Please see Figure 13 , Figure 13 This application provides a schematic diagram of the structure of a computer device, as shown in the embodiment of the present application. Figure 13 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 13 Take a processor 10 as an example.

[0074] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GPA), or any combination thereof.

[0075] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0076] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0077] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0078] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0079] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0080] This application provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method of any embodiment of this application.

[0081] The systems and modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0082] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0083] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] This application is described with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0085] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0086] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0087] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0088] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0089] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0090] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for monitoring gas-liquid two-phase flow in an electrochemical reactor, characterized in that, The method includes: The first neutron imaging information of the flow channel region of the electrochemical reactor is acquired when the reactor is filled with electrolyte and not powered. While the electrochemical reactor is in energized operation, second neutron imaging information of the flow channel region is acquired; Based on the first neutron imaging information and the second neutron imaging information, gas-liquid two-phase distribution parameters in the flow channel region are generated.

2. The method according to claim 1, characterized in that, The gas-liquid two-phase distribution parameters include the gas layer thickness. Based on the first neutron imaging information and the second neutron imaging information, the gas-liquid two-phase distribution parameters in the flow channel region are generated, including: Based on the preset grayscale-neutron transmission intensity mapping relationship, the first neutron imaging information and the second neutron imaging information are converted into the first neutron transmission intensity and the second neutron transmission intensity, respectively. The thickness of the gas layer in the flow channel region is determined based on the ratio of the first neutron transmission intensity to the second neutron transmission intensity.

3. The method according to claim 1, characterized in that, The second neutron imaging information is acquired by a periodic repetitive acquisition mode to capture the dynamic changes of the gas-liquid two-phase flow. The periodic repetitive acquisition mode is configured to acquire two neutron transmission images continuously with an exposure time of 30 seconds in each acquisition cycle, and the interval between adjacent acquisition cycles is 120 seconds.

4. The method according to claim 1, characterized in that, The energized operation state is achieved in the following way: the electrochemical reactor is connected to a DC power supply to receive current, connected to a solution circulation pipeline to drive the electrolyte circulation flow, and connected to a gas collection pipeline to exhaust gas.

5. The method according to claim 1, characterized in that, The electrochemical reactor includes anion exchange membrane water electrolyzer, proton exchange membrane water electrolyzer, alkaline water electrolyzer, polymer electrolyte membrane fuel cell, solid oxide fuel cell, and alkaline fuel cell.

6. The method according to claim 1, characterized in that, Under the energized operating condition, the current density in the electrochemical reactor ranges from 0 to 500 mA / cm². 2 The electrolyte flow rate ranges from 0 to 100 mL / min.

7. The method according to claim 1, characterized in that, The flow field types in the flow channel region include, but are not limited to, parallel flow channels, needle-shaped flow channels, or serpentine flow channels.

8. A monitoring system for gas-liquid two-phase flow in an electrochemical reactor, characterized in that, The system includes: Electrochemical reactor; A neutron imager is used to acquire first neutron imaging information of the flow channel region of the electrochemical reactor when the reactor is filled with electrolyte and not powered; and to acquire second neutron imaging information of the flow channel region when the electrochemical reactor is powered on. The generation module is used to generate gas-liquid two-phase distribution parameters in the flow channel region based on the first neutron imaging information and the second neutron imaging information.

9. A computer device, characterized in that, include: A memory and a processor are communicatively connected, the memory storing computer instructions, and the processor executing the computer instructions to perform the monitoring method for gas-liquid two-phase flow in an electrochemical reactor as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the monitoring method for gas-liquid two-phase flow in the electrochemical reactor according to any one of claims 1 to 7.

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