Method and device for analyzing coupling field in flow battery stack

Abstract

The invention relates to a method and a device for analyzing a coupling field in a flow battery stack. The method comprises the following steps: determining a preset working state of a redox flow battery stack, and controlling a mixed medium in a redox flow circulating system to flow through a battery unit in the preset working state; when the mixed medium flows through the flow channel in the battery unit, image acquisition is carried out on the tracing medium in the mixed medium to obtain a target image, and image processing is carried out; performing kinematics analysis on the image processing result of the tracing medium in the target image to obtain a target motion parameter of the target position of the coupling field and a corresponding statistical parameter; analyzing the state of the target position of the coupling field according to the target motion parameter and the corresponding statistical parameter to obtain a state analysis result of the target position of the coupling field; the state analysis result is used for representing the coupling field state characteristic and the liquid flow time-varying state characteristic of the coupling field target position in the flow battery stack, so that the accuracy and the reliability of the analysis result are improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage batteries, and in particular, to a method and device for analyzing the internal coupled field of a flow battery stack, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] A flow battery stack operates by separating the positive and negative electrolyte solutions and circulating them separately. The reversible oxidation-reduction reaction (i.e., the reversible change in valence state) of the active substances in the positive and negative electrolyte solutions is used to achieve the mutual conversion of electrical energy and chemical energy. The performance and efficiency of a flow battery stack are greatly affected by the design of its internal flow field. The flow field design not only concerns the uniform distribution of the electrolyte solution but also directly affects the heat transfer, mass transfer, and electrochemical reaction rate inside the battery. Therefore, it is one of the keys to the development of flow battery stack technology.

[0003] In the current process of designing the flow field of a flow battery stack, simulation software is usually used to simulate key parameters such as the motion state, pressure distribution, and temperature distribution of the fluid inside the battery. Although the simulation software can quickly predict and optimize the flow field design, it cannot fully reproduce the actual working conditions of the flow battery stack, resulting in low accuracy of the simulation results. Summary of the Invention

[0004] Based on this, it is necessary to provide a method and device for analyzing the internal coupled field of a flow battery stack, a computer device, a computer-readable storage medium, and a computer program product that can improve the accuracy of the analysis results of the internal coupled field of the stack for the above technical problems.

[0005] In a first aspect, the present application provides a method for analyzing the internal coupled field of a flow battery stack. The flow battery stack includes battery units and a liquid flow circulation system connected to the battery units. The method includes:

[0006] Determine the preset working state of the flow battery stack, and control the mixed medium in the liquid flow circulation system to flow through the battery units under the preset working state. The mixed medium includes a tracer medium and a flow battery circulation medium.

[0007] During the process of the mixed medium flowing through the internal flow channels of the battery units, image acquisition is performed on the tracer medium in the battery units to obtain a target image, and image processing is performed.

[0008] Perform kinematic analysis on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position of the coupled field and the statistical parameters corresponding to the target motion parameters. The target position of the coupled field is the actual spatial position during the process of the mixed medium flowing through the battery units.

[0009] Analyze the state of the coupled-field target position according to the target motion parameters and the corresponding statistical parameters of the target motion parameters, and obtain the state analysis result of the coupled-field target position; the state analysis result is used to characterize the coupled-field state characteristics and the liquid flow time-varying state characteristics of the coupled-field target position in the flow battery stack.

[0010] In one embodiment, controlling the mixed medium in the liquid flow circulation system to flow through the battery unit in the preset working state includes:

[0011] Determine the control parameters for the flow battery stack based on the preset working state; the control parameters include process control parameters and attribute control parameters. The process control parameters include type selection parameters for the tracer medium and the flow battery circulation medium, liquid flow control parameters for the mixed medium, and charge-discharge control parameters for charging and discharging the flow battery stack. The type selection parameters are used to determine the types of the tracer medium and the flow battery circulation medium according to the preset working state of the flow battery stack. The liquid flow control parameters are used to control the flow parameters of the mixed medium in the battery unit, and the liquid flow control parameters include at least one of flow rate, pressure, and temperature. The charge-discharge control parameters are used to control the charging state, discharging state, and charge state of the flow battery stack, and the charge-discharge control parameters include at least one of voltage, current, and power. The attribute control parameters are used to control the structure and materials of the flow battery stack;

[0012] Determine the types of the tracer medium and the flow battery circulation medium according to the type selection parameters, and mix the tracer medium and the flow battery circulation medium to form a mixed medium;

[0013] Control the mixed medium in the liquid flow circulation system to flow through the battery unit according to the liquid flow control parameters, and control the battery unit to charge, discharge, or standby according to the charge-discharge control parameters.

[0014] In one embodiment, the preset working state includes a first working state; the first working state is a working state in which the mixed medium is controlled to flow through the battery unit according to the liquid flow control parameters and the battery unit is controlled to charge or discharge according to the charge-discharge control parameters;

[0015] The analyzing the state of the coupled-field target position according to the target motion parameters and the corresponding statistical parameters of the target motion parameters to obtain the state analysis result of the coupled-field target position includes:

[0016] According to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the liquid-phase flow field state at the coupled-field target position in the first working state to obtain a first state analysis result of the coupled-field target position; the first state analysis result is used to characterize the reaction state characteristics and the liquid-flow time-varying state characteristics of the liquid-phase flow field at the coupled-field target position in the liquid flow battery stack in the first working state; the reaction state characteristics are the state characteristics related to the electrochemical reaction at the coupled-field target position in the first working state.

[0017] In one embodiment, in the first working state, the type of the circulating medium of the liquid flow battery is the electrolyte for the liquid flow battery stack, and the tracer medium is at least one of melamine resin microspheres stained with rhodamine-B, natural mineral materials, tracer liquids, and tracer gases. The tracer medium is immiscible with the electrolyte and the tracer medium has tolerance to the electrolyte.

[0018] In one embodiment, the battery cell includes a positive end plate, a negative end plate, a positive electrode assembly, a negative electrode assembly, and an ion exchange membrane. The positive electrode assembly and the negative electrode assembly are clamped between the positive end plate and the negative end plate, and the positive electrode assembly and the negative electrode assembly are respectively disposed on both sides of the ion exchange membrane; the positive electrode assembly includes a positive electrode frame, a positive current collector plate, and a positive electrode plate. A positive electrode reaction cavity is hermetically formed between the positive electrode frame and the ion exchange membrane. The positive electrode plate is disposed in the positive electrode reaction cavity, and the positive electrode plate is electrically and fixedly connected to the positive current collector plate; the negative electrode assembly includes a negative electrode frame, a negative current collector plate, and a negative electrode plate. A negative electrode reaction cavity is hermetically formed between the negative electrode frame and the ion exchange membrane. The negative electrode plate is disposed in the negative electrode reaction cavity, and the negative electrode plate is electrically and fixedly connected to the negative current collector plate.

[0019] When the preset working state is the first working state, the positive end plate, the positive electrode frame, the negative end plate, and the negative electrode frame are made of a transparent material, and the transparent material does not undergo a corrosion reaction with the circulating medium of the liquid flow battery. The positive electrode plate and the negative electrode plate are made of a transparent and conductive material, and the transparent and conductive material does not undergo a corrosion reaction with the circulating medium of the liquid flow battery.

[0020] In one embodiment, the preset working state includes a second working state; the second working state is a working state in which the mixed medium flows through the battery cell according to the liquid flow control parameters and controls the battery cell to standby according to the charge and discharge control parameters.

[0021] Analyzing the state of the coupled-field target position based on the target motion parameters and the corresponding statistical parameters thereof to obtain the state analysis result of the coupled-field target position, including:

[0022] Analyzing the liquid-phase flow field state of the coupled-field target position in the second working state according to the target motion parameters and the corresponding statistical parameters thereof to obtain the second state analysis result of the coupled-field target position; the second state analysis result is used to characterize other state characteristics and time-varying state characteristics of the liquid-phase flow field at the coupled-field target position in the liquid flow battery stack in the second working state; the other state characteristics are state characteristics of the coupled-field target position in the second working state that are irrelevant to the electrochemical reaction.

[0023] In one embodiment, in the second working state, the liquid flow battery circulating medium is defined as a liquid medium with a preset viscosity, and the tracer medium is at least one of melamine resin microspheres stained with rhodamine-B, natural mineral materials, tracer liquids, and tracer gases. The tracer medium is immiscible with the liquid medium with a preset viscosity and the tracer medium has tolerance to the liquid medium with a preset viscosity.

[0024] In one embodiment, the battery unit includes a positive electrode end plate, a negative electrode end plate, a positive electrode assembly, a negative electrode assembly, and an ion exchange membrane. The positive electrode assembly and the negative electrode assembly are clamped between the positive electrode end plate and the negative electrode end plate, and the positive electrode assembly and the negative electrode assembly are respectively arranged on both sides of the ion exchange membrane; the positive electrode assembly includes a positive electrode frame, a positive electrode current collector plate, and a positive electrode plate. A positive electrode reaction chamber is hermetically formed between the positive electrode frame and the ion exchange membrane. The positive electrode plate is arranged in the positive electrode reaction chamber, and the positive electrode plate is electrically and fixedly connected to the positive electrode current collector plate; the negative electrode assembly includes a negative electrode frame, a negative electrode current collector plate, and a negative electrode plate. A negative electrode reaction chamber is hermetically formed between the negative electrode frame and the ion exchange membrane. The negative electrode plate is arranged in the negative electrode reaction chamber, and the negative electrode current collector plate is electrically and fixedly connected to the negative electrode plate;

[0025] When the preset working state is the second working state, the positive electrode end plate, the positive electrode frame, the positive electrode current collector plate, the positive electrode plate, the negative electrode end plate, the negative electrode frame, the negative electrode current collector plate, and the negative electrode plate are made of a transparent material, and the transparent material does not undergo a corrosion reaction with the liquid flow battery circulating medium.

[0026] In one embodiment, the liquid flow circulation system includes a positive electrode circulation loop connected to the positive electrode assembly and a negative electrode circulation loop connected to the negative electrode assembly;

[0027] A positive electrode liquid storage tank and a positive electrode buffer tank are provided on the positive electrode circulation loop. The positive electrode liquid storage tank is communicated with the positive electrode buffer tank, and the positive electrode buffer tank is communicated with the positive electrode assembly of the battery unit. The positive electrode liquid storage tank is used to provide the circulation medium of the positive electrode flow battery, and the positive electrode buffer tank is used to mix the circulation medium of the positive electrode flow battery and the tracer medium to form a mixed medium on the positive electrode side; A negative electrode liquid storage tank and a negative electrode buffer tank are provided on the negative electrode circulation loop. The negative electrode liquid storage tank is communicated with the negative electrode buffer tank, and the negative electrode buffer tank is communicated with the negative electrode assembly of the battery unit. The negative electrode liquid storage tank is used to provide the circulation medium of the negative electrode flow battery, and the negative electrode buffer tank is used to mix the circulation medium of the negative electrode flow battery and the tracer medium to form a mixed medium on the negative electrode side;

[0028] A filling mechanism for providing the tracer medium is further connected to the liquid flow circulation system. The filling includes a positive electrode liquid injection structure provided on the positive electrode circulation loop and a negative electrode liquid injection structure provided on the negative electrode circulation loop. The positive electrode liquid injection structure is used to inject the tracer medium into the positive electrode buffer tank, and the negative electrode liquid injection structure is used to inject the tracer medium into the negative electrode buffer tank; The method of injecting the tracer medium into the positive electrode buffer tank and the negative electrode buffer tank includes at least one of a single-step or periodic step response method or a pulse response method.

[0029] In one embodiment, image acquisition is performed on the tracer medium in the battery unit to obtain a target image, and image processing is performed, including:

[0030] A sheet light source parallel to the flow direction of the mixed medium is applied to the mixed medium in the battery unit at a preset frequency; The sheet light source is used to develop the tracer medium in the mixed medium and form an illuminated flow plane;

[0031] Image acquisition is performed on the flow plane to obtain a target image.

[0032] In one embodiment, kinematic analysis is performed on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position of the coupled field and the statistical parameters corresponding to the target motion parameters, including:

[0033] Obtain two frames of the target images and determine the acquisition time interval between the two frames of the target images;

[0034] Perform image processing on each of the target images to obtain an image processing result, and perform a correlation analysis on the tracer particles in the respective tracer media corresponding to each of the target images based on the image processing result to obtain the cross-correlation parameters between the tracer particles in each of the target images, the displacement of the tracer particles, and the statistical parameters corresponding to the displacement;

[0035] Based on the cross-correlation parameters, the displacement, the statistical parameters corresponding to the displacement, and the acquisition time interval, obtain the target motion parameters of the tracer particles at the target image and the target position of the coupled field and the statistical parameters corresponding to the target motion parameters.

[0036] In one embodiment, two frames of the target images include a first image and a second image. The first image includes a plurality of first sub-images, and the second image includes a plurality of second sub-images corresponding to the first sub-images;

[0037] The performing image processing on each of the target images to obtain an image processing result, and performing a correlation analysis on the tracer particles in the respective tracer media corresponding to each of the target images based on the image processing result to obtain the cross-correlation parameters between the tracer particles in each of the target images, the displacement of the tracer particles, and the statistical parameters corresponding to the displacement includes:

[0038] Determine an image pair according to the first sub-image and the second sub-image corresponding to the first sub-image. For each image pair, determine the position correlation between the tracer particles in the tracer media in the target area of the coupled field for the respective sub-images of the targeted image pair;

[0039] When the position correlation satisfies the correlation analysis condition, perform a Fourier transform on the respective sub-images of the targeted image pair to obtain the frequency-domain images corresponding to the respective sub-images of the targeted image pair and the frequency-domain representations of the tracer particles in the respective frequency-domain images;

[0040] Based on the frequency-domain representations of the tracer particles in the respective sub-images, determine the association relationship between the tracer particles in the respective frequency-domain images;

[0041] Perform an inverse Fourier transform on the frequency-domain images corresponding to the respective sub-images to obtain the spatial images corresponding to the respective frequency images;

[0042] According to the spatial images and the association relationship, determine the association parameters of the tracer particles in the respective sub-images of the targeted image pair;

[0043] Based on the respective associated parameters of each of the images, determine the cross-correlation parameters between the tracer particles in each of the target images, and determine the displacement of the tracer particles between each of the spatial images and the statistical parameters corresponding to the displacement.

[0044] In a second aspect, the present application further provides an analysis device for the coupled fields inside a flow battery stack. The flow battery stack includes battery cells and a liquid flow circulation system connected to the battery cells. The device includes:

[0045] A flow control module, configured to determine a preset operating state of the flow battery stack and control the mixed medium in the liquid flow circulation system to flow through the battery cells in the preset operating state. The mixed medium includes a tracer medium and a flow battery circulation medium.

[0046] An image acquisition module, configured to perform image acquisition on the tracer medium in the battery cells during the process of the mixed medium flowing through the internal flow channels of the battery cells to obtain target images and perform image processing.

[0047] An image analysis module, configured to perform kinematic analysis on the image processing results of the tracer medium in the target images to obtain target motion parameters of the tracer medium at the target positions of the coupled fields and statistical parameters corresponding to the target motion parameters. The target positions of the coupled fields are the actual spatial positions during the process of the mixed medium flowing through the battery cells.

[0048] A state analysis module, configured to analyze the state of the target positions of the coupled fields based on the target motion parameters and the statistical parameters corresponding to the target motion parameters to obtain a state analysis result of the target positions of the coupled fields. The state analysis result is used to characterize the coupled field state characteristics and the liquid flow time-varying state characteristics of the target positions of the coupled fields in the flow battery stack.

[0049] In a third aspect, the present application further provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method described above are implemented.

[0050] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described above are implemented.

[0051] In a fifth aspect, the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method described above are implemented.

[0052] The above-mentioned coupled field analysis method, device, computer equipment, computer-readable storage medium and computer program product for a flow battery stack control the mixed medium in the flow circulation system to flow through the battery cell under a determined preset working state. The mixed medium includes a tracer medium and a flow battery circulation medium. During the process of the mixed medium flowing through the flow channel in the battery cell, image acquisition is performed on the tracer medium in the battery cell to obtain a target image and image processing is carried out. Subsequently, kinematic analysis is performed on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position of the coupled field and the statistical parameters corresponding to the target motion parameters. Finally, according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, the state of the target position of the coupled field is analyzed to obtain the state analysis result of the target position of the coupled field. The state analysis result can characterize the coupled field state characteristics and the flow time-varying state characteristics of the target position of the coupled field in the flow battery stack. By setting different operating conditions using the actual structure of the flow battery stack, kinematic analysis can be performed on the tracer medium in the mixed medium, and the motion state of the flow battery circulation medium can be studied by analyzing the motion state of the tracer medium, so as to reflect the performance impact of the entire mixed medium on the formation process of the target position of the coupled field, thereby obtaining the state analysis result of the target position of the coupled field, which is beneficial to improving the accuracy and reliability of the analysis result. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0054] Figure 1 It is a structural block diagram of a flow battery system targeted by the coupled field analysis method in a flow battery stack in one embodiment;

[0055] Figure 2 In one embodiment Figure 1 It is a schematic structural diagram of a battery cell;

[0056] Figure 3 It is a schematic flowchart of the coupled field analysis method in a flow battery stack in one embodiment;

[0057] Figure 4 It is a schematic flowchart of determining the cross-correlation parameter in one embodiment;

[0058] Figure 5 It is a structural block diagram of the coupled field analysis device in a flow battery stack in one embodiment;

[0059] Figure 6 It is the internal structure diagram of a computer device in an embodiment.

[0060] Reference numerals in the specification:

[0061] Battery unit 210, positive end plate 211a, positive electrode frame 211b, positive current collector plate 211c, positive electrode plate 211d, negative end plate 212a, negative electrode frame 212b, negative current collector plate 212c, negative electrode plate 212d, ion exchange membrane 213, positive circulation loop 221, positive liquid storage tank 221a, positive buffer tank 221b, negative circulation loop 222, negative liquid storage tank 222a, negative buffer tank 222b, positive liquid injection structure 231, negative liquid injection structure 232, sheet light source 241, camera 242, image processor 250. Specific embodiments

[0062] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0063] The method for analyzing the internal coupled field of a flow battery stack provided by an embodiment of the present application can be applied to an application environment including a terminal and a server. Among them, the terminal communicates with the server through a network. The data storage system can store the data that the server needs to process. The data storage system can be integrated on the server, or placed in the cloud or other network servers. Among them, the terminal can be but is not limited to various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted device can be a virtual reality (VR) device, an augmented reality (AR) device, a smart glasses, etc. The server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0064] In an exemplary embodiment, as Figure 1 shown, it is the structural schematic diagram of the flow battery system targeted when analyzing the internal coupled field in the present application. The flow battery system includes a flow battery stack, a filling mechanism, a photographing mechanism and an image processor 250. Among them:

[0065] The flow battery stack includes battery cells 210 and a liquid flow circulation system connected to the battery cells 210. Flow channels for guiding a medium (such as electrolyte or other media with the same or similar properties as the electrolyte) are provided inside the battery cells 210. The medium in the liquid flow circulation system can flow directionally through the flow channels under the drive of an external force and form a coupled field target position in the battery cells 210. According to the different working states of the flow battery stack, the coupled field target position can include a flow field, an electric field, a temperature field, etc.

[0066] As Figure 2 shown, the battery cell 210 includes a positive end plate 211a, a negative end plate 212a, a positive electrode assembly, a negative electrode assembly, and an ion exchange membrane 213. The positive electrode assembly and the negative electrode assembly are clamped between the positive end plate 211a and the negative end plate 212a, and the positive electrode assembly and the negative electrode assembly are respectively arranged on both sides of the ion exchange membrane 213. The positive electrode assembly includes a positive electrode frame 211b, a positive electrode current collector plate 211c, and a positive electrode plate 211d. A positive electrode reaction chamber is hermetically formed between the positive electrode frame 211b and the ion exchange membrane 213. The positive electrode plate 211d is arranged in the positive electrode reaction chamber, and the positive electrode current collector plate 211c is electrically and fixedly connected to the positive electrode plate 211d, so that the positive electrode plate 211d can be connected to an external power supply through the positive electrode current collector plate 211c. When the positive electrode electrolyte enters the positive electrode reaction chamber, the positive electrode electrolyte contacts the positive electrode plate 211d but does not contact the positive electrode current collector plate 211c, so that the positive electrode plate 211d can react with the positive electrode electrolyte after being energized through the positive electrode current collector plate 211c. The negative electrode assembly includes a negative electrode frame 212b, a negative electrode current collector plate 212c, and a negative electrode plate 212d. A negative electrode reaction chamber is hermetically formed between the negative electrode frame 212b and the ion exchange membrane 213. The negative electrode plate 212d is arranged in the negative electrode reaction chamber, and the negative electrode current collector plate 212c is electrically and fixedly connected to the negative electrode plate 212d, so that the negative electrode plate 212d can be connected to an external power supply through the negative electrode current collector plate 212c. When the negative electrode electrolyte enters the negative electrode reaction chamber, the negative electrode electrolyte contacts the negative electrode plate 212d but does not contact the negative electrode current collector plate 212c, so that the negative electrode plate 212d can react with the negative electrode electrolyte after being energized through the negative electrode current collector plate 212c. The positive electrode reaction chamber and the negative electrode reaction chamber are isolated by the ion exchange membrane. Flow channels are provided in the positive end plate 211a, the positive electrode frame 211b, the positive electrode current collector plate 211c, the positive electrode plate 211d, the negative end plate 212a, the negative electrode frame 212b, the negative electrode current collector plate 212c, and the negative electrode plate 212d to distribute the flow rate of the incoming medium.

[0067] According to the different positive and negative poles, the liquid flow circulation system includes an independent positive pole circulation loop 221 and a negative pole circulation loop 222. The positive pole circulation loop 221 is provided with a positive pole liquid storage tank 221a and a positive pole buffer tank 221b. The positive pole circulation loop 221 is connected to the positive pole assembly. The positive pole circulation loop 221 transports the medium from the positive pole liquid storage tank 221a to the positive pole buffer tank 221b, and injects it into the positive pole assembly through the positive pole liquid inlet provided on the positive pole end plate 211a, so that the medium flows into each flow channel on the positive pole side, and then flows back to the positive pole liquid storage tank 221a from the positive pole liquid outlet, and circulates in this way. Similarly, the negative pole circulation loop 222 is provided with a negative pole liquid storage tank 222a and a negative pole buffer tank 222b. The negative pole circulation loop 222 is connected to the negative pole assembly. The negative pole circulation loop 222 transports the medium from the negative pole liquid storage tank 222a to the negative pole buffer tank 222b, and injects it into the negative pole assembly through the negative pole liquid inlet provided on the negative pole end plate 212a, so that the medium flows into each flow channel on the negative pole side, and then flows back to the negative pole liquid storage tank 222a from the negative pole liquid outlet, and circulates in this way.

[0068] The filling mechanism is used to provide the tracer medium. The filling mechanism includes a positive pole liquid injection structure 231 provided on the positive pole circulation loop 221 and a negative pole liquid injection structure 232 provided on the negative pole circulation loop 222. The positive pole liquid injection structure 231 and the negative pole liquid injection structure 232 are used to inject the tracer medium into the corresponding positive pole buffer tank 221b and negative pole buffer tank 222b respectively, so that the tracer medium can be mixed with the original medium in the liquid flow circulation system and then flow into the flow channels of the battery unit 210.

[0069] In an exemplary embodiment, the method of injecting the tracer medium into the positive pole buffer tank 221b and the negative pole buffer tank 222b includes at least one of a single or periodic step response method or a pulse response method.

[0070] Among them, "single - time" means performing the step - response method or the pulse - response method only once. "Periodic" means, based on performing the step - response method or the pulse - response method once, injecting the tracer medium multiple times at a certain period. Periodically injecting the tracer medium can help coordinate with the charge - discharge process of the flow - battery stack to fully understand the coupling - field state characteristics of the target positions in the flow - battery stack and the time - varying state characteristics of the liquid flow during each stage of the entire charge - discharge cycle. For example, after injecting the tracer medium once using the step - response method or the pulse - response method and determining that all the tracer medium has flowed out of the battery cell, periodically repeat injecting the tracer medium into the battery cell again according to the step - response method or the pulse - response method. Specifically, record the time parameters of each injection of the tracer medium, and the injection time matches the real - time working conditions of the working state of the battery cell (i.e., the first working state and the second working state described later). In addition, by setting a detector at the outlet of the battery cell, observe and record the residence time and its distribution of the tracer medium in the battery cell each time, so as to further understand the influence of the internal structure and working state of the battery cell on the flow state of the circulating medium.

[0071] Taking the positive - electrode buffer tank 211b as an example, the step - response method means that when injecting the tracer medium into the positive - electrode buffer tank 221b, input a step signal at the inlet of the positive - electrode buffer tank 211b, and continuously input the tracer medium with a first preset concentration into the positive - electrode buffer tank 211b through the inlet of the positive - electrode buffer tank 211b under the continuous action of the step signal, or switch the liquid - flow circulating medium and use the tracer medium under the same flow conditions, so that there is a step - like jump in the concentration of the tracer medium at the inlet of the positive - electrode buffer tank 211b. At the same time, continuously detect the first real - time concentration of the tracer medium at the outlet of the positive - electrode buffer tank 211b until the first real - time concentration matches the first preset concentration to complete the injection of the tracer medium. The matching of the first real - time concentration and the first preset concentration can include that the two are equal, the concentration difference between the two is within a certain range, or the two satisfy certain concentration conditions, etc.

[0072] The pulse - response method means inputting a pulse signal at the inlet of the positive - electrode buffer tank 211b, instantaneously injecting the tracer medium with a second preset concentration through the inlet of the positive - electrode buffer tank 211b under the action of the pulse signal, and synchronously detecting the second real - time concentration at the outlet of the positive - electrode buffer tank 211b until the second real - time concentration meets the conditions to complete the injection of the tracer medium. The conditions that the second real - time concentration meets can include that the second real - time concentration is 0 or other preset values, and can also include that the second real - time concentration matches the second preset concentration, etc. For the injection of the tracer medium into the negative - electrode buffer tank 211b, the positive - electrode buffer tank 211b can be referred to.

[0073] The imaging module is used to collect images of the mixed medium in the battery cell 210 to obtain a target image. The imaging module includes a light source assembly and a camera 242. The light source assembly can irradiate the medium flowing through the battery cell 210 to make the tracer medium develop, so as to form a visualized flow plane in the flow channel. The camera 242 is used to capture the flow plane to obtain a target image. Specifically, the light source assembly includes sheet light sources 241 respectively arranged on one side of the positive end plate 211a, one side of the negative end plate 212a and the bottom of the battery cell 210, and the sheet light sources 241 are perpendicular to the corresponding positive end plate 211a, negative end plate 212a and the bottom of the battery cell 210. Each sheet light source 241 works in cooperation with a camera 242, and the camera 242 is implemented by a CCD / CMOS camera. When the sheet light source 241 irradiates the mixed medium, the cooperating camera 242 takes a picture synchronously once to collect images of the flow condition of the medium inside the positive electrode assembly, the flow condition of the medium inside the negative electrode assembly, and the electrochemical reaction condition inside the positive electrode assembly and the negative electrode assembly respectively. Specifically, the sheet light source can be implemented by at least one of light sources such as double-pulse ruby laser, Ar-ion laser, Nd:YAG laser, Rudy laser, YAG double-pulse laser, etc.

[0074] The image processor 250 is communicatively connected to the imaging module to obtain the target image collected by the camera 242 and analyze the target image to obtain the state analysis result of the coupled field target position.

[0075] In one embodiment, as Figure 3 shown, a method for analyzing the coupled field in a flow battery stack is provided. Taking the application of this method to a server as an example for illustration, it can be understood that this method can also be applied to a terminal, and can also be applied to a system including a terminal and a server, which is realized through the interaction between the terminal and the server. In this embodiment, taking the analysis of the above flow battery system as an example, the method of this embodiment includes:

[0076] Step 301, determine the preset working state of the flow battery stack, and control the mixed medium in the liquid flow circulation system to flow through the battery cell in the preset working state.

[0077] Among them, the preset working state refers to the working conditions or states preset for the flow battery stack before operation. The preset working state includes, but is not limited to, the working state of the flow battery stack (such as charge and discharge, idle, etc.), the voltage and current of charge and discharge, as well as the flow rate and flow of the electrolyte. By setting the flow battery stack to operate under different states and conditions, the operating parameters of the flow battery stack under the corresponding working conditions or states can be obtained, thereby realizing the analysis of the coupling field state characteristics and the time-varying state characteristics of the liquid flow at the target position of the coupling field inside the flow battery stack, including, but not limited to, the analysis of the performance such as the generation and dynamic parameters of the coupling field. The coupling field state characteristics refer to the state of the component structures such as the ion exchange membrane, the positive electrode plate, the negative electrode plate, the positive electrode frame, and the negative electrode frame in the positive reaction chamber and the negative reaction chamber where the flow battery stack is located, mainly in the solid phase. The coupling field state characteristics include, but are not limited to, the characteristics of other physical fields (such as temperature field, concentration field, etc.) except the flow field. The time-varying state characteristics of the liquid flow refer to the situation of the flow field changing with time.

[0078] Among them, the mixed medium refers to a mixture containing a tracer medium and a flow battery circulating medium. The tracer medium refers to a substance that provides contrast or marking during the image acquisition process to more accurately analyze the flow of the mixed medium. The flow battery circulating medium is immiscible with the tracer medium. Depending on the working state of the flow battery stack, different media can be used for the flow battery circulating medium. When the battery cell does not need to be charged or discharged, the flow battery circulating medium can be defined as a liquid medium with a preset viscosity. For example, distilled water or deionized water is used and other viscous substances are added to adjust the viscosity of the liquid medium to replace the original electrolyte for liquid flow circulation. When the battery cell needs to be charged or discharged, the flow battery circulating medium can be replaced by an electrolyte or a substance with the same or similar properties as the electrolyte to restore the liquid phase flow field under real working conditions. The tracer medium is insoluble in the flow battery circulating medium but can be fully mixed with the flow battery circulating medium under the action of an external force. Correspondingly, when the battery cell does not need to be charged or discharged, the tracer medium can be realized by a medium that is immiscible with the liquid medium with a preset viscosity and is tolerant to the liquid medium with a preset viscosity. When the battery cell needs to be charged or discharged, the tracer medium can be realized by a medium that is immiscible with the electrolyte or other substances with the same or similar properties as the electrolyte and is tolerant to the electrolyte and other substances with the same or similar properties as the electrolyte, so as not to affect the redox reaction between the positive and negative plates and the flow battery circulating medium. Specifically, when implemented, the tracer medium can adopt at least one of rhodamine-B stained melamine resin microspheres, natural mineral materials, tracer liquids, and tracer gases. Among them, the dyes stained with rhodamine-B include but are not limited to rhodamine 6G, rhodamine BB, rhodamine B Extra, and rhodamine BG, etc. The natural mineral materials include but are not limited to aluminum powder, silicon dioxide, titanium dioxide, talcum powder, etc. The tracer liquids include but are not limited to atomized paraffin oil, atomized silicone oil, etc. The tracer gases include but are not limited to oxygen bubbles, hydrogen bubbles, etc.

[0079] In an exemplary embodiment, the tracer medium is implemented by tracer particles, and the particle density of the tracer particles is 1.1 ± 0.1 g / cm 3 , and the particle diameter of the tracer particles is 10 ± 2 μm (the diameter selection range of the tracer particles is 1 - 1000 μm).

[0080] Specifically, the flow battery circulating medium is stored in the corresponding positive and negative liquid storage tanks. Driven by the circulation pump in the liquid flow circulation system, the flow battery circulating medium can flow in the liquid flow circulation system. The tracer medium is injected into the liquid flow circulation system under the action of the filling device, and after being mixed with the flow battery circulating medium in the corresponding buffer tank to form a mixed medium, it continues to enter the battery cell under the drive of the circulation pump.

[0081] Exemplarily, the server controls the mixed medium in the liquid flow circulation system of the flow battery stack to flow through the battery cells according to the determined preset working state of the flow battery stack.

[0082] Step 302: During the process of the mixed medium flowing through the internal flow channels of the battery cells, image acquisition is performed on the tracer medium in the battery cells to obtain a target image, and image processing is carried out.

[0083] Among them, image acquisition refers to the process of using a photographing device to take pictures of the flowing process of the mixed medium in the battery cells to obtain a target image containing the tracer medium, so as to capture the flowing situation of the tracer medium in the internal flow channels of the battery cells. The target image refers to the image containing the flowing situation of the tracer medium obtained through image acquisition.

[0084] Exemplarily, during the process of the mixed medium flowing through the internal flow channels of the battery cells, the server performs image acquisition on the tracer medium in the battery cells to obtain a target image, and image processing is carried out.

[0085] In an exemplary embodiment, to facilitate image acquisition of the interior of the battery cells, the battery cells in this embodiment are made of a transparent material, and the original design structures of each component are retained. Specifically, the positive end plate, positive electrode frame, positive current collector plate, positive electrode plate, negative end plate, negative electrode frame, negative current collector plate, and negative electrode plate can all be made of a transparent material to replace the original material for experiments. Moreover, according to different analysis objectives, different transparent materials can also be used. The transparent material refers to a material through which the opposite side can be observed, such as a fully transparent or semi-transparent material, or a material with other transparency levels. In this way, making the positive end plate, positive electrode frame, positive current collector plate, positive electrode plate, negative end plate, negative electrode frame, negative current collector plate, and negative electrode plate of a transparent material is conducive to observing the internal medium flow situation, the structure of the flow channels, and the electrochemical reaction situation at the electrode plates (including the positive electrode plate and the negative electrode plate) through structures such as the positive end plate, positive electrode frame, positive current collector plate, positive electrode plate, negative end plate, negative electrode frame, negative current collector plate, and negative electrode plate, and then acquiring a target image containing the tracer medium.

[0086] For example, when only analyzing the flow of the electrolyte, since there is no need for the battery cell to have charge and discharge capabilities, at this time, transparent materials or translucent materials can be used to replace the positive end plate, positive electrode frame, positive current collector plate, positive electrode plate, negative end plate, negative electrode frame, negative current collector plate, and negative electrode plate in the battery cell, etc.; the transparent materials or translucent materials can be realized by, for example, quartz glass plates, polymethyl methacrylate plates (acrylic), or polycarbonate plates. When replacing, it is not required that the replaced structure has functionality, and only the geometric dimensions of each structure need to be replicated and restored, and a liquid with a viscosity similar to that of the flow battery stack system and non-corrosive liquid can be used to replace the electrolyte. In this case, the flow battery circulation medium can adopt a liquid medium with a refractive index consistent with or close to that of the aforementioned material, and the flow battery circulation medium adopts a liquid medium with a preset viscosity, and the preset viscosity refers to a viscosity similar to that of the electrolyte under actual working conditions to increase the accuracy of the analysis results.

[0087] Preferably, the positive electrode plate, negative electrode plate, positive current collector plate, and negative current collector plate can be made of a material with transparency and conductivity, and the material with transparency and conductivity does not undergo a corrosion reaction with the flow battery circulation medium. With such a setting, it is possible to analyze the state of the liquid phase flow field and the target position of the coupling field in the first working state and the second working state in the same set of devices, and it is also beneficial to the integrated setting of the positive electrode plate and the positive current collector plate and the integrated setting of the negative electrode plate and the negative current collector plate. In some other embodiments, other conductive materials with permeability can also be used to achieve this. Specifically, when implementing, the conductive material with transparency can include, but is not limited to, one or more of materials such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), and poly(3,4-ethylenedioxythiophene) (PEDOT); the conductive material with permeability can adopt a metal wire mesh or a conductive fiber mesh.

[0088] For another example, when it is necessary to analyze the electrochemical reaction process between the electrolyte and the electrode plate, since the battery unit needs to have the ability to charge and discharge, at this time, according to the properties of the electrolyte, transparent or semi-transparent conductive polymer materials or other permeable conductive materials with relevant tolerance are used to replace the positive electrode frame, positive current collector plate, positive electrode plate, negative electrode frame, negative current collector plate and negative electrode plate, and transparent or semi-transparent polymer materials with similar mechanical strength are used to replace the positive and negative end plates to avoid corrosion reactions between the circulating medium of the flow battery and the transparent materials; specifically, the transparent or semi-transparent polymer material can be a polyvinyl chloride plate or a polystyrene plate with acid-base tolerance, and the refractive index of the polymer material is the same as or close to the refractive index of the electrolyte used. Compared with non-transparent materials, using transparent materials to make the positive electrode frame, positive current collector plate, positive electrode plate, negative electrode frame, negative current collector plate and negative electrode plate can improve the image quality of the tracer particles captured in the flow battery stack. The positive and negative side reaction chambers are centered on the ion exchange membrane. The reaction chambers can be sealed with corrosion-resistant sealing wires or gaskets, and sealed by pressing and clamping through the two end plates, or a hot melt film can be used. After heating and melting, it is then sealed by pressing and clamping through the two end plates, so as to observe the flow channels inside the battery unit through the positive and negative end plates, and observe the electrode reaction area through the side surfaces of the positive and negative electrode frames.

[0089] When the flow battery stack is charged and discharged based on structures such as the transparent positive electrode frame, positive current collector plate, positive electrode plate, negative electrode frame, negative current collector plate and negative electrode plate, the leakage conditions inside and outside the flow battery stack can also be observed, which is conducive to analyzing the leakage reasons of the flow battery stack through structures such as the transparent positive electrode frame and negative electrode frame, so as to modify and optimize the internal structure and / or sealing method of the flow battery stack.

[0090] It is understandable that in some other embodiments, a micro camera can also be used to follow the mixed medium flowing into the flow channel to collect the target image. In this case, the structure of the flow battery stack does not need to be replaced, so as to more truly restore the working state of the flow battery stack.

[0091] Step 303: Perform kinematic analysis on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position in the coupled field and the statistical parameters corresponding to the target motion parameters.

[0092] Among them, kinematic analysis refers to the process of calculating and analyzing motion parameters such as velocity, acceleration, displacement, vorticity intensity, etc. of the tracer medium in the target image, so as to obtain the target motion parameters and the statistical parameters corresponding to the target motion parameters, facilitate understanding the flow of the tracer medium in the flow channel, and thus evaluate the coupling field state characteristics and the time-varying state characteristics of the liquid flow at the coupling field target position in the flow battery stack. The statistical parameters corresponding to the target kinematic parameters may include at least one of parameters such as mean, variance, standard deviation, etc.

[0093] Among them, the coupling field target position refers to the actual spatial position of the mixed medium during the process of flowing through the battery unit. The coupling field refers to at least one of the flow field, temperature field, and concentration field generated during the process of the mixed medium flowing through the battery unit, or the field formed by the superposition of at least one of the flow field, temperature field, and concentration field and the electric field. The flow field is generated when the medium in the flow battery stack flows through the flow channel. The flow field is used to characterize the space and state of the medium flowing in the flow channel, including but not limited to parameters such as flow velocity, flow direction, and pressure distribution. The aforementioned parameters can jointly determine the transmission efficiency and the electrochemical reaction rate of the medium in the battery unit, etc. The temperature field is the field formed by the temperature distribution of the medium at different positions in the flow battery stack. The temperature field is used to characterize the relationship between the changes in physical quantities such as flow rate, pressure, and temperature of the medium at different spatial positions in the flow channel and the charge and discharge state and current density. The concentration field is used to characterize the valence state changes, composition changes, and other side reactions that occur during the electrochemical reaction when the electrolyte and its active substances in the positive reaction chamber and the negative reaction chamber of the flow battery stack flow through different spatial positions. The electric field is generated when the medium in the flow battery stack flows through the flow channel and combines with the electrochemical reaction process between the medium and the electrode plate. The electric field is used to characterize the spatial region formed by the potential difference existing between the electrode plates, including but not limited to parameters such as charge distribution, electric field intensity distribution, potential difference, and direction. The aforementioned parameters can jointly determine the electrochemical reaction rate of the battery unit, the output power of the battery, the transmission efficiency of the battery, etc.

[0094] Exemplarily, the server calculates and analyzes fluid kinematic parameters such as velocity, acceleration, displacement, streamline degree, vorticity, etc. for the tracer medium in the acquired target image, so as to obtain the target motion parameters of the tracer medium at the coupling field target position and the statistical parameters corresponding to the target motion parameters.

[0095] Step 304, analyze the state of the coupling field target position according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, and obtain the state analysis result of the coupling field target position.

[0096] Among them, the state analysis result refers to the result obtained by analyzing the coupled-field state and the time-varying state of the liquid flow at the coupled-field target position based on the target motion parameters and the statistical parameters corresponding to the target motion parameters. The state analysis result is used to characterize the coupled-field state characteristics and the time-varying state characteristics of the liquid flow at the coupled-field target position in the flow battery stack, such as flow efficiency, stability, energy conversion efficiency, etc., so as to evaluate the flow state of the medium inside the flow battery stack and the reaction state between the electrode plate and the electrolyte under charge and discharge conditions, and to timely discover potential problems and make optimization adjustments.

[0097] Exemplarily, the server analyzes the coupled-field state and the time-varying state of the liquid flow at the coupled-field target position according to parameters such as the velocity, acceleration, displacement, streamline degree, vorticity, etc. of the coupled-field target position and the mean value, variance, standard deviation, etc. of the parameters such as the velocity, acceleration, displacement, streamline degree, vorticity, etc., and obtains the state analysis result of the coupled-field target position.

[0098] In an alternative embodiment, since a sheet light source and a camera are provided in the directions perpendicular to the positive electrode plate plane, the negative electrode plate plane, and the bottom plane of the battery unit, during the analysis, the cameras at each position synchronously collect the target images at the corresponding positions. The server can respectively perform kinematic analysis on the image processing results of the tracer medium in each target image to obtain the target motion parameters of the coupled-field target position in each target image of the tracer medium and the statistical parameters corresponding to the target motion parameters. Subsequently, the server can respectively perform state analysis according to the target motion parameters corresponding to each coupled-field target position and the statistical parameters corresponding to the target motion parameters to obtain the state analysis result corresponding to each coupled-field target position. Then, the analysis results corresponding to each coupled-field target position are fused to obtain the state analysis result of the entire coupled field, so as to provide data support for the analysis of the fluid state of the entire coupled field of the battery unit; the fusion methods include but are not limited to at least one of splicing, weighting, dimension elevation (such as two-dimensional to three-dimensional), synthesis, and averaging to obtain the state analysis result of the entire coupled field.

[0099] In the above method for analyzing the coupled fields in a flow battery stack, the mixed medium in the liquid flow circulation system is controlled to flow through the battery cell under a determined preset working state. The mixed medium includes a tracer medium and a flow battery circulation medium. During the process of the mixed medium flowing through the internal flow channels of the battery cell, image acquisition is performed on the tracer medium in the battery cell to obtain a target image, and image processing is carried out. Subsequently, kinematic analysis is performed on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position of the coupled field and the statistical parameters corresponding to the target motion parameters. Finally, based on the target motion parameters and the statistical parameters corresponding to the target motion parameters, the state of the target position of the coupled field is analyzed to obtain the state analysis result of the target position of the coupled field. The state analysis result can characterize the coupled field state characteristics and the liquid flow time-varying state characteristics of the target position of the coupled field in the flow battery stack. By setting different operating conditions using the actual structure of the flow battery stack, kinematic analysis can be performed on the tracer medium in the mixed medium, and the motion state of the flow battery circulation medium can be studied by analyzing the motion state of the tracer medium, thereby reflecting the performance impact of the entire mixed medium on the formation process of the target position of the coupled field, and thus obtaining the state analysis result of the target position of the coupled field, which is beneficial to improving the accuracy and reliability of the analysis result.

[0100] In one embodiment, controlling the mixed medium in the liquid flow circulation system to flow through the battery cell under a preset working state includes:

[0101] Determining control parameters for the flow battery stack based on the preset working state; the control parameters include process control parameters and attribute control parameters. The process control parameters include type selection parameters for the tracer medium and the flow battery circulation medium, liquid flow control parameters for the mixed medium, and charge-discharge control parameters for charging and discharging the flow battery stack; determining the types of the tracer medium and the flow battery circulation medium according to the type selection parameters, and controlling the tracer medium and the flow battery circulation medium to be mixed to form a mixed medium; controlling the mixed medium in the liquid flow circulation system to flow through the battery cell according to the liquid flow control parameters, and controlling the battery cell to charge, discharge, or standby according to the charge-discharge control parameters.

[0102] Among them, the type selection parameter is a parameter used to determine the types of the tracer medium and the liquid flow battery circulation medium according to the preset working state of the liquid flow battery stack. When analyzing the coupling field state characteristics and the time-varying state characteristics of the liquid flow at the coupling field target position, different type selection parameters can be set according to different working states of the liquid flow battery stack to restore the true working state of the liquid flow battery stack. The liquid flow control parameter is a parameter used to describe and control the flow state of the mixed medium in the liquid flow circulation system. The liquid flow control parameters include, but are not limited to, flow rate, pressure, temperature, etc., and are used to ensure that the mixed medium can flow through the battery unit in the expected manner. The liquid flow control parameters can also include parameters such as pump power, output flow rate, head, and pump loss (including the transportation loss of the internal circulation pipeline in the liquid flow circulation system, the common flow channel in the stack, and the pressure loss formed by the manifold channels in the stack). The charge-discharge control parameter is a parameter used to control the charge state, discharge state, or standby state of the liquid flow battery stack. The charge-discharge control parameters include at least one of voltage, current, and power, and are used to ensure that the positive and negative plates can be charged, discharged, or standby in the expected manner. The standby state refers to the working state in which the liquid flow battery stack is neither charging nor discharging but maintaining the liquid flow circulation.

[0103] The property control parameter is used to control the structure and materials of the liquid flow battery stack. For the property control parameter, it can affect the liquid-phase flow field parameters in the liquid flow battery stack. Through relevant structural designs, the liquid-phase flow field in the liquid flow battery stack can be influenced from the aspects of structural form design and material function selection, so as to change the local flow pattern, flow state, flow velocity (flow rate), and its regional distribution, etc. in the liquid-phase flow field of the liquid flow battery stack, thereby changing the performance of the stack during the charge-discharge process. The property control parameters include, but are not limited to, the material property parameters and flow channel parameters distributed on the electrode frame, the material property parameters and flow channel parameters distributed on the electrode plates (positive electrode plate, negative electrode plate), and the viscosity of the electrolyte, etc.

[0104] For specific implementation, please refer to Figure 2, the right side of the figure shows the A1 view and A2 view of the negative electrode side structure A (including the negative electrode frame 212b, the negative electrode current collector plate 212c, and the negative electrode plate 212d), and the B1 view and B2 view of the positive electrode side structure B (including the positive electrode frame 211b, the positive electrode current collector plate 211c, and the positive electrode plate 212d). For the negative electrode side structure, in the A2 view, the parameters on the distributed electrode frame include the diameter and specific flow rate of the common flow channel in the negative electrode frame 212b (distributed in region C1) and the topological structure, geometric shape, and liquid flow distribution form of the manifold channels in the negative electrode frame 212b (distributed between region C2 and region C3). The parameters distributed on the electrode reaction region include the flow channel form and parameters in the reaction region of the negative electrode plate 212d (including the flow channels on the electrode and the flow channels on the bipolar plate), other forms and parameters affecting the flow pattern in the reaction region of the negative electrode plate 212d (such as parameters such as the fiber diameter, porosity, permeability, thickness, intrusion region, and depth of the porous electrode, the electrode compression ratio, materials and structures that can affect the contact mode between the electrode and the electrolyte), and the fluid pressure drop in the reaction region of the negative electrode plate 212d (related to the electrochemical reaction at the interface between the electrode and the electrolyte during charge and discharge) (distributed in region C3). For the positive electrode side structure, in the B2 view, the parameters on the distributed electrode frame include the diameter and specific flow rate of the common flow channel in the positive electrode frame 211b (distributed in region D1) and the topological structure, geometric shape, and liquid flow distribution form of the manifold channels in the positive electrode frame 211b (distributed between region D2 and region D3). The parameters distributed on the electrode reaction region include the flow channel form and parameters in the reaction region of the positive electrode plate 211d (including the flow channels on the electrode and the flow channels on the bipolar plate), other forms and parameters affecting the flow pattern in the reaction region of the positive electrode plate 211d (such as parameters such as the fiber diameter, porosity, permeability, thickness, intrusion region, and depth of the porous electrode, the electrode compression ratio, materials and structures that can affect the contact mode between the electrode and the electrolyte), and the fluid pressure drop in the reaction region of the positive electrode plate 211d (related to the electrochemical reaction at the interface between the electrode and the electrolyte during charge and discharge) (distributed in region D3). In an exemplary embodiment, according to the mechanical structure of the battery cells in the flow battery stack, the extreme pressure values at the positive electrode inlet and the negative electrode inlet can be set to 0.3 Mpa to control the pressure at the positive electrode inlet and the negative electrode inlet not to exceed 0.5 m 3 / h. Specifically, taking the flow rate as an example, according to different preset working states, the flow rate of the mixed medium can be set to 0.3 m 3 / h, 0.35 m 3 / h, 0.4 m 3 / h, 0.45 m 3 / h to obtain the evolution law of the interaction between different operating conditions and the flow field under the same structure of the battery cells.

[0105] Exemplarily, the server determines type selection parameters, liquid flow control parameters, and charge and discharge control parameters for the flow battery stack based on a preset working state, determines the types of the tracer medium and the flow battery circulation medium according to the type selection parameters, and controls the tracer medium and the flow battery circulation medium to be mixed to form a mixed medium; controls the mixed medium in the liquid flow circulation system to flow through the battery unit according to the liquid flow control parameters, and controls the battery unit to charge, discharge, or standby according to the charge and discharge control parameters.

[0106] In this embodiment, by determining the type selection parameters, liquid flow control parameters, and charge and discharge control parameters of the mixed medium based on the preset working state, effectively controlling the mixed medium in the liquid flow circulation system to flow through the battery unit according to the liquid flow control parameters, and controlling the battery unit to charge, discharge, or standby according to the charge and discharge control parameters, it can ensure that the battery unit operates under specified working conditions and conditions, so as to facilitate targeted analysis of the operating conditions of the flow battery stack.

[0107] In one embodiment, the preset working state includes a first working state.

[0108] Among them, the first working state refers to the working state of controlling the mixed medium to flow through the battery unit according to the liquid flow control parameters and controlling the battery unit to charge or discharge according to the charge and discharge control parameters. In the first working state, the mixed medium enters the positive and negative electrode frames. The flow battery circulation medium in the mixed medium uses the electrolyte for the flow battery stack or a substance having the same or similar properties as the electrolyte. The tracer medium uses at least one of rhodamine-B stained melamine resin microspheres, natural mineral materials, tracer liquids, and tracer gases. The tracer medium is immiscible with the electrolyte and the tracer medium has tolerance to the electrolyte, so that the flow battery circulation medium can undergo an electrochemical reaction with the positive and negative electrode plates.

[0109] Based on this, according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the state of the coupled field target position to obtain the state analysis result of the coupled field target position, including:

[0110] According to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the liquid phase flow field state of the coupled field target position in the first working state to obtain the first state analysis result of the coupled field target position.

[0111] Among them, the first state analysis result refers to the result obtained by analyzing the state of the coupled-field target position based on the target motion parameters and the corresponding statistical parameters of the target motion parameters. The first state analysis result is used to characterize the reaction state characteristics and the time-varying state characteristics of the liquid-phase flow field at the coupled-field target position in the liquid flow battery stack under the first working state. The reaction state characteristics refer to the state characteristics related to the electrochemical reaction at the coupled-field target position under the first working state.

[0112] Exemplarily, the server analyzes parameters such as the velocity, acceleration, displacement, vorticity intensity, liquid concentration, temperature, etc. of the mixed medium (or tracer medium) at the coupled-field target position and parameters such as the voltage and current of the electric field under the first working state according to the target motion parameters and the corresponding statistical parameters of the target motion parameters, and obtains the first state analysis result of the coupled-field target position.

[0113] In this embodiment, by analyzing the state of the coupled field formed by superimposing at least one of the flow field and the temperature field generated when the mixed medium flows through the flow channels of the battery unit under the first working state in combination with the target motion parameters and the corresponding statistical parameters of the target motion parameters, the charge and discharge performance of the liquid flow battery stack and the flow characteristics of the mixed medium can be understood, which is beneficial to providing data support for optimizing the battery design and improving the charge and discharge management strategy.

[0114] In an alternative embodiment, in the case of the first working state, the positive end plate, the positive electrode frame, the negative end plate, and the negative electrode frame are made of a transparent material, and the transparent material does not undergo a corrosion reaction with the circulating medium of the liquid flow battery to facilitate the acquisition of images of the tracer medium. The positive electrode plate and the negative electrode plate are made of a transparent and conductive material, and the transparent and conductive material does not undergo a corrosion reaction with the circulating medium of the liquid flow battery. The positive current collector plate and the negative current collector plate can also be made of a permeable conductive material, such as using a metal wire mesh or a conductive fiber mesh as the conductive skeleton structure. Such a setting is beneficial to the integrated setting of the positive electrode plate and the positive current collector plate and the integrated setting of the negative electrode plate and the negative current collector plate, and is beneficial to taking pictures from an angle perpendicular to the positive end plate, the negative end plate, and the bottom of the battery unit, and the shooting field of view is clear and transparent. Specifically, when implemented, the transparent and conductive material can include, but is not limited to, one or more of materials such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), and poly(3,4-ethylenedioxythiophene) (PEDOT); the material with the characteristics of the conductive skeleton structure includes, but is not limited to, a two-dimensional or three-dimensional network structure woven from corrosion-resistant metal wires, metal fibers, conductive polymer fibers, metal-coated fibers, etc.

[0115] In one embodiment, the preset working state includes a second working state.

[0116] Among them, the second working state refers to the working state in which the mixed medium flows through the battery unit according to the liquid flow control parameters and the battery unit stands by according to the charge and discharge control parameters. At this time, the flow battery stack is not charged or discharged, and only the mixed medium flows in the flow channel. In the second working state, the mixed medium enters the positive and negative electrode frames, and the liquid flow battery circulating medium in the mixed medium is defined as a liquid medium with a preset viscosity. The tracer medium is at least one of rhodamine-B stained melamine resin microspheres, natural mineral materials, tracer liquids, and tracer gases. The tracer medium is immiscible with the liquid medium with a preset viscosity and the tracer medium is tolerant to the liquid medium with a preset viscosity.

[0117] Based on this, according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the liquid-phase flow field state of the coupled-field target position to obtain the state analysis result of the coupled-field target position, including:

[0118] According to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the liquid-phase flow field state of the coupled-field target position in the second working state to obtain the second state analysis result of the coupled-field target position.

[0119] Among them, the second state analysis result refers to the result obtained by analyzing the liquid-phase flow field state of the coupled-field target position according to the target motion parameters and the statistical parameters corresponding to the target motion parameters. The second state analysis result is used to characterize other state characteristics and liquid flow time-varying state characteristics at the coupled-field target position in the flow battery stack in the second working state. Other state characteristics refer to the state characteristics that are irrelevant to the electrochemical reaction at the coupled-field target position in the second working state.

[0120] Exemplarily, the server analyzes parameters such as the velocity, acceleration, displacement, and vortex intensity of the mixed medium (or tracer medium) at the coupled-field target position in the second working state according to the target motion parameters and the statistical parameters corresponding to the target motion parameters to obtain the first state analysis result of the mixed medium (or tracer medium) at the coupled-field target position in the second working state.

[0121] In this embodiment, by combining the target motion parameters and the statistical parameters corresponding to the target motion parameters to analyze the state of at least one of the flow field and the temperature field generated when the mixed medium flows through the battery unit flow channel in the second working state or the state of the coupled field formed by multiple fields, it is possible to understand the influence of the flow channel in the flow battery stack on the flow characteristics of the mixed medium, which is beneficial to further providing data support for optimizing the battery design and improving the charge and discharge management strategy.

[0122] In an exemplary embodiment, in the case of the second operating state, the positive end plate, the positive electrode frame, the positive current collector plate, the positive electrode plate, the negative end plate, the negative electrode frame, the negative current collector plate, and the negative electrode plate are made of a material with transparency, and the liquid flow circulation medium is a fluid with a viscosity equivalent to that of the actual liquid flow circulation medium but does not react with the material with transparency, so as to facilitate the acquisition of images of the tracer medium.

[0123] In one embodiment, images of the tracer medium in the battery cell are acquired to obtain target images, including:

[0124] A sheet light source parallel to the flow direction of the mixed medium is applied to the mixed medium in the battery cell at a preset frequency. The sheet light source is used to develop the tracer medium in the mixed medium and form an illuminated flow plane; images of the flow plane are acquired to obtain target images.

[0125] Among them, the preset frequency refers to the frequency at which the sheet light source irradiates the mixed medium. The sheet light source is usually implemented by a laser light source, so that when it irradiates the tracer medium in the mixed medium, the tracer medium can be developed and a luminous flow plane is formed in the illuminated area. The sheet light source refers to a light beam with a relatively thin thickness, a certain width, and brightness formed by reflecting the laser light source with an optical lens.

[0126] Among them, the flow direction of the mixed medium refers to the direction in which the mixed medium flows from the liquid inlet to the liquid outlet in the battery cell.

[0127] Among them, acquiring images of the flow plane refers to the process of acquiring images of the plane where the luminous tracer medium is located after the tracer medium in the mixed medium is illuminated by the sheet light source. During the acquisition process, the acquisition frequency of the camera usually matches the flashing or luminous frequency (i.e., the preset frequency) of the sheet light source, so that when the tracer medium in the flow is displaced, the influence of time is ignored due to the rapid flashing of the sheet light source, so as to facilitate the acquisition of multiple frames of target images within a short time interval.

[0128] Exemplarily, the server controls the sheet light source at the corresponding position to irradiate the mixed medium in the battery cell at a preset frequency, so that the light beam of the sheet light source is projected into the mixed medium along a direction parallel to the flow direction of the mixed medium, so that the tracer medium in the mixed medium is developed and an illuminated flow plane is formed; subsequently, the server acquires images of the flow plane formed by the illuminated tracer medium to obtain target images.

[0129] In this embodiment, the tracer medium in the mixed medium is irradiated by the sheet light source, so that the tracer medium can emit light when irradiated and form a flow plane, ensuring that the camera can successfully acquire target images.

[0130] In one embodiment, kinematic analysis is performed on the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position in the coupled field and the statistical parameters corresponding to the target motion parameters, including:

[0131] Acquire two frames of target images and determine the acquisition time interval between the two frames of target images; perform image processing on each target image respectively to obtain the image processing results, and based on the image processing results, perform correlation analysis on the tracer particles in the respective tracer media in each target image to obtain the cross-correlation parameters between the target images, and determine the displacements of the tracer particles in the target image and the statistical parameters corresponding to the displacements; based on the cross-correlation parameters, displacements, statistical parameters corresponding to the displacements, and time interval, obtain the target motion parameters of the tracer particles at the target position in the coupled field and the statistical parameters corresponding to the target motion parameters.

[0132] Among them, the acquisition time interval refers to the time difference between the acquisitions of two frames of target images, which is used to reflect the time span between adjacent images in the image frame sequence or between two frames of target images to be analyzed. Image processing refers to the process of processing the target image through a statistical method of a local query window to remove the noise effect and determine the displacements of the tracer particles in different target images. Correlation analysis refers to the process of analyzing the correlation between the tracer particles in the target image based on the spatial transformation of the image coordinates. The representation of the target image of the tracer particle in the time domain is obtained based on pixel features, and each pixel feature has its specific position coordinates and gray value. In the frequency domain, the target image is represented as a combination of different frequency components, and these frequency components correspond to different features in the image, such as edges, textures, etc. The process of converting the image from the time domain to the frequency domain refers to converting the target image from the time domain to the frequency domain through a transformation algorithm (such as Fourier transform, etc.) to perform filtering, enhancement, etc. on the target image in the frequency domain, and after the processing is completed, converting the target image back to the time domain through an inverse transformation algorithm (such as inverse Fourier transform, etc.).

[0133] Among them, the cross-correlation parameter refers to a parameter determined based on the cross-correlation method and used to reflect the similarity or correlation degree between two frames of target images based on pixel features, so as to determine the relationship between the motion or position change states of the tracer medium in the two frames of target images.

[0134] Exemplarily, the server obtains two target images from the target images captured by the camera and determines the acquisition time interval between the two target images. These two images can be two adjacent target images in the image frame sequence, or two non-adjacent (cross-time interval) target images that meet the requirements. Then, the server performs image processing on each target image respectively to obtain the image processing results, and based on the image processing results, performs correlation analysis on the tracer particles in the respective tracer media corresponding to each target image to obtain the cross-correlation parameters between the target images, and determines the displacements of the tracer particles in each target image and the statistical parameters corresponding to the displacements; finally, the server obtains the target motion parameters of the tracer particles at the target position in the coupled field and the mean, variance, standard deviation, etc. corresponding to the target motion parameters based on the cross-correlation parameters, displacements, statistical parameters corresponding to the displacements, and time interval.

[0135] In this embodiment, by combining image processing and cross-correlation analysis to analyze the two target images, the target motion parameters at the target position in the coupled field and the statistical parameters corresponding to the target motion parameters can be accurately determined, which is beneficial to providing a reliable data basis for subsequent motion analysis, performance evaluation, and optimization.

[0136] In one embodiment, the two target images include a first image and a second image. The first image includes a plurality of first sub-images, and the second image includes a plurality of second sub-images corresponding to the first sub-images. The first sub-images and the second sub-images can be determined from the corresponding images by using the statistical method of a local query window, can be determined by equally dividing the first image and the second image by area, or can be determined by non-equally dividing the first image and the second image according to the key areas and non-key areas in the target images.

[0137] Based on this, as Figure 4 shown, image processing is performed on each target image respectively to obtain the image processing results, and based on the image processing results, correlation analysis is performed on the tracer particles in the respective tracer media corresponding to each target image to obtain the cross-correlation parameters between the tracer particles in each target image, as well as the displacements of the tracer particles and the statistical parameters corresponding to the displacements, including:

[0138] Step 401, determine the image pairs according to the first sub-images and the second sub-images corresponding to the first sub-images. For each image pair, determine the position correlation between the tracer particles in the tracer medium in the target area of the coupled field of the respective sub-images of the image pair targeted.

[0139] Among them, an image pair refers to a pair composed of a first sub-image and a second sub-image corresponding to the first sub-image, and is used to analyze the positional relationship and displacement data of the tracer particles between the acquisition time of the first sub-image and the acquisition time of the second sub-image. The coupled field target area refers to the area in the image pair where the tracer particles are located.

[0140] Positional correlation means that the positions of the tracer particles in the tracer medium in the coupled field target area in the first sub-image are related to the positions of the tracer particles in the tracer medium in the coupled field target area in the second sub-image, that is, they may be tracer particles in the tracer medium or tracer particles in adjacent areas. When the positions of the tracer particles in the coupled field target area determined in the first sub-image are related to the positions of the corresponding tracer particles in the coupled field target area in the second sub-image, it can be used as the basis for determining subsequent cross-correlation parameters. Specifically, the positional correlation between the tracer particles in the coupled field target area in the first sub-image and the tracer particles in the coupled field target area in the second sub-image can be determined by using Pearson correlation coefficient, mutual information parameter, etc.

[0141] Exemplarily, the server can determine the first sub-image and the second sub-image corresponding to the first sub-image, and determine the first sub-image and the corresponding second sub-image as an image pair. Subsequently, for each image pair, the server determines the positional correlation between the tracer particles in the tracer medium in the coupled field target area of each sub-image of the image pair targeted.

[0142] In an exemplary embodiment, the second sub-image is an image obtained after the tracer particles move on the basis of the first sub-image. The relationship between the second sub-image and the first sub-image can be expressed as:

[0143] f2(x,y) = f1(x + Δx, y + Δy) (1)

[0144] From this, the relationship between the target image containing the first sub-image and the second sub-image can be expressed as:

[0145] F(x,y) = f1(x,y) + f2(x + Δx, y + Δy) (2)

[0146] Among them, f1(x,y) and f2(x,y) are the function expressions of the first sub-image and the second sub-image respectively, (x,y) is the position coordinate in the time domain of the center of the tracer particle combination (or the center of the first sub-image and the second sub-image), and Δx, Δy are the displacements of the center of the tracer particle combination.

[0147] Step 402, when the position correlation meets the correlation analysis condition, perform Fourier transform on each sub-image of the targeted image pair to obtain the frequency-domain image corresponding to each sub-image of the targeted image pair and the frequency-domain representation of the tracer particles in each frequency-domain image.

[0148] Among them, the correlation analysis condition refers to the condition set for the correlation between the positions of the tracer particles in the coupled-field target region of the first sub-image and the positions of the tracer particles in the coupled-field target region of the second sub-image, which can be represented by a correlation threshold. When the position correlation exceeds the correlation threshold, it is considered that the tracer particles in the coupled-field target region of the first sub-image are correlated with the tracer particles in the coupled-field target region of the second sub-image, and subsequent analysis can be carried out. Otherwise, if they are not correlated, it is necessary to continue to determine the tracer particle images of the coupled-field target regions with correlation in the first sub-image and the second sub-image.

[0149] Fourier transform is used to transform each sub-image from the time domain (or spatial domain) to the frequency domain to analyze the frequency components in each sub-image. The frequency-domain image refers to the image obtained through Fourier transform, which represents the representation of the image in the frequency domain to show the intensity and distribution of different frequency components in the image. The frequency-domain representation of the tracer particles in each frequency-domain image is the manifestation form of the tracer particles in the frequency-domain image, which is used to reflect the frequency characteristics of the tracer particles in the spatial distribution.

[0150] Exemplarily, the server can compare the position correlation between the tracer particles in the tracer medium of each sub-image of the targeted image pair with the set correlation analysis condition, and when the position correlation meets the correlation analysis condition, perform Fourier transform on each sub-image of the targeted image pair to obtain the frequency-domain image corresponding to each sub-image of the targeted image pair and the frequency-domain representation of the tracer particles in each frequency-domain image.

[0151] In an exemplary embodiment, the first frequency-domain image obtained after Fourier transform of the first sub-image is expressed as:

[0152]

[0153] Among them, is the function expression of the first frequency-domain image, ω x , ω y is the frequency-domain representation of the center of the tracer medium combination in the frequency domain, and i is the i-th image pair.

[0154] Among them, the second frequency-domain image obtained after Fourier transform of the second sub-image is expressed as:

[0155]

[0156] Among them, is the functional expression of the second frequency-domain image, ω x , ω y is the frequency-domain representation of the center of the tracer medium combination in the frequency domain.

[0157] In some other embodiments, when performing image transformation, it can also be implemented by means of fast Fourier transform, discrete cosine transform, wavelet transform, fractional Fourier transform, quantum Fourier transform, etc.

[0158] Step 403, based on the frequency-domain representations of the tracer particles in each sub-image, determine the correlation relationships between the tracer particles in each frequency-domain image.

[0159] Among them, the correlation relationship refers to the connection or similarity existing between the tracer particles in different frequency-domain images, and can be determined by comparing the positions, intensities or other attributes of the particles in different frequency-domain images.

[0160] Exemplarily, the server can determine the correlation relationships between the tracer particles in each frequency-domain image based on the frequency-domain representations of the tracer particles in each sub-image and according to the correlation algorithm. The correlation algorithm can be one or more of algorithms such as Pearson correlation coefficient, mutual information parameter, etc.

[0161] In an exemplary embodiment, the correlation relationships between the tracer particles in each frequency-domain image can be determined based on performing a parallel transformation on the first frequency-domain image and the second frequency-domain image. The correlation relationship between the first frequency-domain image and the second frequency-domain image is expressed as:

[0162]

[0163] Furthermore, the correlation relationship between the first sub-image and the second sub-image in the target image can be represented by a cross-correlation function. By solving the cross-correlation function, the correlation relationship between the first sub-image and the second sub-image can be obtained. Among them, the cross-correlation function is expressed as:

[0164] F 12 (x, y) = ∑f1(x, y)·f2(x + Δx, y + Δy) (6)

[0165] Among them, F 12 (x, y) is the cross-correlation function of the first sub-image and the second sub-image.

[0166] When solving the cross-correlation function, by determining the respective maximum values x max , y max of x and y in the function, x max , y maxThat is, the position coordinates of the tracer particle in the second sub-image, which are the best matching positions in the second sub-image corresponding to those in the first sub-image.

[0167] When performing image segmentation, sub-pixel method and Gaussian fitting method can be used to optimize the best matching positions to improve the calculation accuracy of the position coordinates. At the same time, the frequency domain expression of the cross-correlation function is conducive to quickly solving the best position coordinates in the image function.

[0168] Step 404: Perform inverse Fourier transform on the frequency domain images corresponding to each sub-image to obtain the spatial images corresponding to each frequency image.

[0169] Among them, the inverse Fourier transform refers to the process of converting the frequency domain image back to the time domain image. The inverse Fourier transform is the inverse process of the Fourier transform and is used to reconstruct the cross-correlation data in the target image from the frequency domain information through the inverse Fourier transform. The time domain image is opposite to the frequency domain image, and the time domain image can be used to intuitively reflect information such as the position change of the tracer particle in the image.

[0170] Exemplarily, the server can perform inverse Fourier transform on the frequency domain images corresponding to each sub-image to obtain the spatial images corresponding to each frequency image.

[0171] In an exemplary embodiment, the process of performing inverse Fourier transform on the corresponding frequency domain images is usually determined by complex conjugate multiplication, specifically expressed as:

[0172]

[0173] Among them, F'(x, y) is the function expression of the spatial image corresponding to each frequency image after the inverse Fourier transform.

[0174] Substituting the correlation relationship between the first frequency domain image and the second frequency domain image in the above formula (5) into formula (7), the spatial image obtained after the inverse Fourier transform of the frequency image can be expressed as:

[0175]

[0176] Step 405: Determine the correlation parameters of the tracer particles in each sub-image of the targeted image pair according to the spatial image and the correlation relationship.

[0177] Among them, the correlation parameter is an index used to describe the correlation between tracer particles in different sub-images, including but not limited to the displacement, velocity, acceleration, etc. of the tracer particles.

[0178] Exemplarily, the server determines the correlation parameters of the tracer particles in each sub-image of the targeted image pair according to the spatial image and the correlation relationship.

[0179] Step 406: Based on the respective correlation parameters corresponding to each image, determine the cross-correlation parameters between the tracer particles in each target image, and determine the displacements of the tracer particles between each spatial image and the statistical parameters corresponding to the displacements.

[0180] Exemplarily, the server can, based on the respective correlation parameters corresponding to each image, determine the cross-correlation parameters between the tracer particles in each target image, the displacements of each tracer particle, and the mean, variance, standard deviation, etc. corresponding to the displacements. When determining the cross-correlation parameters, the server can fuse the respective correlation parameters to obtain the cross-correlation parameters. The fusion methods include but are not limited to at least one of weighting, splicing, dimension elevation (such as two-dimensional to three-dimensional), synthesis, mean calculation, etc.

[0181] In this embodiment, by determining the relevant image pairs, the position correlation of the tracer particles in the target area of the coupled field can be accurately determined, and the Fourier transform and inverse Fourier transform are used to efficiently process the image data in the frequency domain to reveal the dynamic correlation between the tracer particles, which is beneficial to improving the accuracy of determining the cross-correlation parameters of the position relationship of the tracer particles in the target image.

[0182] In one embodiment, the above method further includes:

[0183] Obtain the spectrum of the second frequency-domain image; the spectrum contains several spectral signals; fuse the spectral signals, and correct the second frequency-domain image according to the fusion result to obtain the corrected second frequency-domain image.

[0184] Wherein, the spectrum refers to the representation of each frequency vector in the second frequency-domain image in the frequency domain, which is used to display the intensity or amplitude of different frequency components in the frequency vector. The spectral signal refers to each component or element in the spectrum. Fusion refers to the process of integrating each spectral signal to improve the integrity, accuracy, and reliability of the data. The fusion process includes but is not limited to weighted average, maximum value, minimum value, or other fusion strategies. The corrected second frequency-domain image refers to the image obtained by adjusting or modifying the original second frequency-domain image according to the fusion result to improve the quality and accuracy of the image.

[0185] Exemplarily, the server obtains the spectrum of the second frequency-domain image based on the frequency vectors included in the second frequency-domain image; and fuses the spectral signals, and corrects the second frequency-domain image according to the fusion result to obtain the corrected second frequency-domain image.

[0186] In this embodiment, by correcting the second frequency-domain image, the corrected second frequency-domain image can be used for subsequent processing with the original first frequency-domain image to improve the accuracy and precision of image processing, and thus more reliable cross-correlation parameters can be obtained in the subsequent analysis process.

[0187] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the indications of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0188] Based on the same inventive concept, an embodiment of the present application further provides a device for analyzing the internal coupled field of a flow battery stack for implementing the method for analyzing the internal coupled field of a flow battery stack described above. The solution provided by this device for solving problems is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the device for analyzing the internal coupled field of a flow battery stack provided below can refer to the limitations on the method for analyzing the internal coupled field of a flow battery stack in the above text, and will not be repeated here.

[0189] In an exemplary embodiment, as Figure 5 shown, a device for analyzing the internal coupled field of a flow battery stack is provided, including: a flow control module 501, an image acquisition module 502, an image analysis module 503, and a state analysis module 504, where:

[0190] The flow control module 501 is configured to determine a preset working state of the flow battery stack and control the mixed medium in the liquid flow circulation system to flow through the battery unit in the preset working state; the mixed medium includes a tracer medium and a flow battery circulation medium.

[0191] The image acquisition module 502 is configured to perform image acquisition on the tracer medium in the battery unit during the process of the mixed medium flowing through the internal flow channel of the battery unit, obtain a target image, and perform image processing.

[0192] The image analysis module 503 is configured to perform kinematic analysis on the image processing result of the tracer medium in the target image to obtain target motion parameters of the tracer medium at the target position of the coupled field and statistical parameters corresponding to the target motion parameters; the target position of the coupled field is the actual spatial position during the process of the mixed medium flowing through the internal flow channel of the battery unit.

[0193] A state analysis module 504 is configured to analyze the state of the coupled-field target position according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, so as to obtain a state analysis result of the coupled-field target position; the state analysis result is used to characterize the coupled-field state characteristics and the liquid flow time-varying state characteristics of the coupled-field target position in the flow battery stack.

[0194] In an optional embodiment, the flow control module 501 is further configured to determine control parameters for the flow battery stack based on a preset working state; the control parameters include process control parameters and attribute control parameters. The process control parameters include type selection parameters for the tracer medium and the flow battery circulation medium, flow control parameters for the mixed medium, and charge-discharge control parameters for charging and discharging the flow battery stack. The type selection parameters are used to determine the types of the tracer medium and the flow battery circulation medium according to the preset working state of the flow battery stack. The flow control parameters are used to control the flow parameters of the mixed medium in the battery unit. The flow control parameters include at least one of flow rate, pressure, and temperature. The charge-discharge control parameters are used to control the charging state, discharging state, and charge state of the flow battery stack. The charge-discharge control parameters include at least one of voltage, current, and power. The attribute control parameters are used to control the structure and materials of the flow battery stack; determine the types of the tracer medium and the flow battery circulation medium according to the type selection parameters, and mix the tracer medium and the flow battery circulation medium to form a mixed medium; control the mixed medium in the liquid flow circulation system to flow through the battery unit according to the flow control parameters, and control the battery unit to charge, discharge, or standby according to the charge-discharge control parameters.

[0195] In an optional embodiment, the image acquisition module 502 is further configured to apply a sheet light source parallel to the flow direction of the mixed medium to the mixed medium in the battery unit at a preset frequency; the sheet light source is used to develop the tracer medium in the mixed medium and form an illuminated flow plane; perform image acquisition on the flow plane to obtain a target image.

[0196] In an optional embodiment, the image analysis module 503 is further configured to obtain two frames of target images and determine the acquisition time interval between the two frames of target images; perform image processing on each target image respectively to obtain an image processing result, and perform correlation analysis on the tracer particles in the respective tracer media corresponding to each target image based on the image processing result to obtain the cross-correlation parameters between the target images and the displacement of the tracer particles and the statistical parameters corresponding to the displacement; based on the cross-correlation parameters, displacement, statistical parameters corresponding to the displacement, and time interval, obtain the target motion parameters of the tracer particles at the coupled-field target position and the statistical parameters corresponding to the target motion parameters.

[0197] In an alternative embodiment, the two target images include a first image and a second image. The first image includes a plurality of first sub-images, and the second image includes a plurality of second sub-images corresponding to the first sub-images. The first sub-images and the second sub-images can be determined from the corresponding images by using the statistical method of a local query window, or can be determined by equally dividing the first image and the second image according to equal areas. The image analysis module 503 is further configured to determine an image pair according to the first sub-images and the second sub-images corresponding to the first sub-images. For each image pair, determine the position correlation between the tracer particles in the tracer medium in the coupled field target region of each sub-image of the targeted image pair; when the position correlation satisfies the correlation analysis condition, perform a Fourier transform on each sub-image of the targeted image pair to obtain the frequency-domain images corresponding to each sub-image of the targeted image pair and the frequency-domain representations of the tracer particles in each frequency-domain image; based on the frequency-domain representations of the tracer particles in each sub-image, determine the correlation relationship between the tracer particles in each frequency-domain image; perform an inverse Fourier transform on the frequency-domain images corresponding to each sub-image to obtain the spatial images corresponding to each frequency image; according to the spatial images and the correlation relationship, determine the correlation parameters of the tracer particles in each sub-image of the targeted image pair; based on the correlation parameters corresponding to each image pair, determine the cross-correlation parameters between the tracer particles in each target image, and determine the displacement between the tracer particles in each spatial image and the statistical parameters corresponding to the displacement.

[0198] In an alternative embodiment, the image analysis module 503 is further configured to obtain the frequency spectrum of the second frequency image; the frequency spectrum contains a plurality of frequency spectrum signals; fuse the frequency spectrum signals, and correct the second frequency image according to the fusion result to obtain a corrected second frequency image.

[0199] In an alternative embodiment, the preset working state includes a first working state, which is a working state of controlling the mixed medium to flow through the battery unit according to the liquid flow control parameters and controlling the battery unit to charge or discharge according to the charge and discharge control parameters. The state analysis module 504 is further configured to analyze the liquid-phase flow field state at the coupled field target position in the first working state according to the target motion parameters and the statistical parameters corresponding to the target motion parameters, to obtain a first state analysis result of the coupled field target position; the first state analysis result is used to characterize the reaction state characteristics and the liquid flow time-varying state characteristics of the liquid-phase flow field at the coupled field target position in the liquid flow battery stack in the first working state; the reaction state characteristics are the state characteristics related to the electrochemical reaction at the coupled field target position in the first working state.

[0200] In an alternative embodiment, the preset working state includes a second working state, which is a working state in which the mixed medium flows through the battery unit according to the liquid flow control parameters and the battery unit is controlled to standby according to the charge-discharge control parameters. The state analysis module 504 is further configured to analyze the liquid-phase flow field state at the coupled-field target position in the second working state according to the target motion parameter and the statistical parameter corresponding to the target motion parameter, so as to obtain a second state analysis result of the coupled-field target position; the second state analysis result is used to characterize other state characteristics and time-varying state characteristics of the liquid-phase flow field at the coupled-field target position in the flow battery stack in the second working state; the other state characteristics are state characteristics unrelated to the electrochemical reaction at the coupled-field target position in the second working state.

[0201] Each module in the above-mentioned coupled-field analysis device in the flow battery stack can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor in the computer device in the form of hardware or be independent of the processor, or can be stored in the memory in the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0202] In an exemplary embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 6 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data such as preset working states, target images, target motion parameters, and state analysis results. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a method for analyzing the coupled field in a flow battery stack.

[0203] Those skilled in the art can understand that Figure 6 the structure shown in

[0204] In an exemplary embodiment, a computer device is provided, which includes a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the method for analyzing the internal coupled field of the flow battery stack in the above embodiment is implemented.

[0205] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method for analyzing the internal coupled field of the flow battery stack in the above embodiment is implemented.

[0206] In an embodiment, a computer program product is provided, which includes a computer program. When the computer program is executed by a processor, the method for analyzing the internal coupled field of the flow battery stack in the above embodiment is implemented.

[0207] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0208] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0209] The above-described embodiments only represent several implementation manners of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of this application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A method for analyzing the coupled fields inside a flow battery stack, characterized in that, The flow battery stack includes battery cells and a liquid flow circulation system connected to the battery cells; the method includes: Determining a preset operating state of the flow battery stack, and controlling a mixed medium in the liquid flow circulation system to flow through the battery cells in the preset operating state; the mixed medium includes a tracer medium and a flow battery circulation medium; During the process of the mixed medium flowing through the internal flow channels of the battery cells, image acquisition is performed on the tracer medium in the battery cells to obtain a target image, and image processing is performed; Performing kinematic analysis on the image processing result of the tracer medium in the target image to obtain target motion parameters of the tracer medium at a target position in the coupled field and statistical parameters corresponding to the target motion parameters; the target position in the coupled field is the actual spatial position during the process of the mixed medium flowing through the battery cells; Analyzing the state of the target position in the coupled field according to the target motion parameters and the statistical parameters corresponding to the target motion parameters to obtain a state analysis result of the target position in the coupled field; the state analysis result is used to characterize the coupled field state characteristics and the liquid flow time-varying state characteristics of the target position in the coupled field of the flow battery stack.

2. The method according to claim 1, characterized in that, The controlling the mixed medium in the liquid flow circulation system to flow through the battery cells in the preset operating state includes: Determining control parameters for the flow battery stack based on the preset operating state; the control parameters include process control parameters and attribute control parameters, the process control parameters include type selection parameters for the tracer medium and the flow battery circulation medium, liquid flow control parameters for the mixed medium, and charge-discharge control parameters for charging and discharging the flow battery stack, the type selection parameters are used to determine the types of the tracer medium and the flow battery circulation medium according to the preset operating state of the flow battery stack, the liquid flow control parameters are used to control the flow parameters of the mixed medium in the battery cells, the liquid flow control parameters include at least one of flow rate, pressure, and temperature, the charge-discharge control parameters are used to control the charging state, discharging state, and charge state of the flow battery stack, the charge-discharge control parameters include at least one of voltage, current, and power, and the attribute control parameters are used to control the structure and materials of the flow battery stack; Determining the types of the tracer medium and the flow battery circulation medium according to the type selection parameters, and mixing the tracer medium and the flow battery circulation medium to form a mixed medium; Controlling the mixed medium in the liquid flow circulation system to flow through the battery cells according to the liquid flow control parameters, and controlling the battery cells to charge, discharge, or standby according to the charge-discharge control parameters.

3. The method according to claim 2, characterized in that, The preset operating state includes a first operating state; the first operating state is an operating state of controlling the mixed medium to flow through the battery cells according to the liquid flow control parameters and controlling the battery cells to charge or discharge according to the charge-discharge control parameters; Analyzing the state of the coupled-field target position according to the target motion parameters and the corresponding statistical parameters of the target motion parameters to obtain the state analysis result of the coupled-field target position, including: Analyzing the liquid-phase flow field state of the coupled-field target position in the first working state according to the target motion parameters and the corresponding statistical parameters of the target motion parameters to obtain the first state analysis result of the coupled-field target position; the first state analysis result is used to characterize the reaction state characteristics and the time-varying state characteristics of the liquid flow at the coupled-field target position in the liquid flow battery stack in the first working state; the reaction state characteristics are the state characteristics related to the electrochemical reaction at the coupled-field target position in the first working state.

4. The method according to claim 3, wherein In the first working state, the type of the circulating medium of the flow battery is the electrolyte for the flow battery stack, and the tracer medium adopts at least one of rhodamine-B stained melamine resin microspheres, natural mineral materials, tracer liquids and tracer gases. The tracer medium is immiscible with the electrolyte and the tracer medium has tolerance to the electrolyte.

5. The method according to claim 3, wherein The battery cell includes a positive electrode end plate, a negative electrode end plate, a positive electrode assembly, a negative electrode assembly and an ion exchange membrane. The positive electrode assembly and the negative electrode assembly are clamped between the positive electrode end plate and the negative electrode end plate, and the positive electrode assembly and the negative electrode assembly are respectively arranged on both sides of the ion exchange membrane; the positive electrode assembly includes a positive electrode frame, a positive electrode current collector plate and a positive electrode plate. A positive electrode reaction chamber is hermetically formed between the positive electrode frame and the ion exchange membrane. The positive electrode plate is arranged in the positive electrode reaction chamber, and the positive electrode plate is electrically and fixedly connected to the positive electrode current collector plate; the negative electrode assembly includes a negative electrode frame, a negative electrode current collector plate and a negative electrode plate. A negative electrode reaction chamber is hermetically formed between the negative electrode frame and the ion exchange membrane. The negative electrode plate is arranged in the negative electrode reaction chamber, and the negative electrode plate is electrically and fixedly connected to the negative electrode current collector plate. When the preset working state is the first working state, the positive electrode end plate, the positive electrode frame, the negative electrode end plate and the negative electrode frame are made of a transparent material, and the transparent material does not undergo a corrosion reaction with the circulating medium of the flow battery. The positive electrode plate and the negative electrode plate are made of a transparent and conductive material, and the transparent and conductive material does not undergo a corrosion reaction with the circulating medium of the flow battery.

6. The method according to claim 2, wherein The preset working state includes a second working state; the second working state is the working state in which the mixed medium flows through the battery cell according to the liquid flow control parameters and controls the battery cell to standby according to the charge and discharge control parameters. Analyzing the state of the coupled-field target position according to the target motion parameters and the corresponding statistical parameters of the target motion parameters to obtain the state analysis result of the coupled-field target position, including: According to the target motion parameters and the statistical parameters corresponding to the target motion parameters, analyze the liquid-phase flow field state at the coupled-field target position in the second working state, and obtain the second-state analysis result of the coupled-field target position; the second-state analysis result is used to characterize other state characteristics and time-varying state characteristics of the liquid-phase flow field at the coupled-field target position in the liquid flow battery stack in the second working state; the other state characteristics are state characteristics that are irrelevant to the electrochemical reaction at the coupled-field target position in the second working state.

7. The method according to claim 6, wherein In the second working state, the circulating medium of the flow battery is defined as a liquid medium with a preset viscosity, and the tracer medium is at least one of melamine resin microspheres stained with rhodamine-B, natural mineral materials, tracer liquids, and tracer gases. The tracer medium is immiscible with the liquid medium with a preset viscosity and the tracer medium has tolerance to the liquid medium with a preset viscosity.

8. The method according to claim 5, wherein The battery unit includes a positive electrode end plate, a negative electrode end plate, a positive electrode assembly, a negative electrode assembly, and an ion exchange membrane. The positive electrode assembly and the negative electrode assembly are clamped between the positive electrode end plate and the negative electrode end plate, and the positive electrode assembly and the negative electrode assembly are respectively arranged on both sides of the ion exchange membrane; the positive electrode assembly includes a positive electrode frame, a positive electrode current collector plate, and a positive electrode plate. A positive electrode reaction chamber is hermetically formed between the positive electrode frame and the ion exchange membrane, the positive electrode plate is arranged in the positive electrode reaction chamber, and the positive electrode plate is electrically and fixedly connected to the positive electrode current collector plate; the negative electrode assembly includes a negative electrode frame, a negative electrode current collector plate, and a negative electrode plate. A negative electrode reaction chamber is hermetically formed between the negative electrode frame and the ion exchange membrane, the negative electrode plate is arranged in the negative electrode reaction chamber, and the negative electrode current collector plate is electrically and fixedly connected to the negative electrode plate. When the preset working state is the second working state, the positive electrode end plate, the positive electrode frame, the positive electrode current collector plate, the positive electrode plate, the negative electrode end plate, the negative electrode frame, the negative electrode current collector plate, and the negative electrode plate are made of a transparent material, and the transparent material does not undergo a corrosion reaction with the circulating medium of the flow battery.

9. The method according to claim 5 or 8, characterized in that, The liquid flow circulation system includes a positive electrode circulation loop connected to the positive electrode assembly and a negative electrode circulation loop connected to the negative electrode assembly. A positive electrode liquid storage tank and a positive electrode buffer tank are provided on the positive electrode circulation loop. The positive electrode liquid storage tank is communicated with the positive electrode buffer tank, and the positive electrode buffer tank is communicated with the positive electrode assembly of the battery unit. The positive electrode liquid storage tank is used to provide the circulation medium of the positive electrode flow battery, and the positive electrode buffer tank is used to mix the circulation medium of the positive electrode flow battery and the tracer medium and form a mixed medium on the positive electrode side; A negative electrode liquid storage tank and a negative electrode buffer tank are provided on the negative electrode circulation loop. The negative electrode liquid storage tank is communicated with the negative electrode buffer tank, and the negative electrode buffer tank is communicated with the negative electrode assembly of the battery unit. The negative electrode liquid storage tank is used to provide the circulation medium of the negative electrode flow battery, and the negative electrode buffer tank is used to mix the circulation medium of the negative electrode flow battery and the tracer medium and form a mixed medium on the negative electrode side; A filling mechanism for providing the tracer medium is further connected to the liquid flow circulation system. The filling includes a positive electrode liquid injection structure provided on the positive electrode circulation loop and a negative electrode liquid injection structure provided on the negative electrode circulation loop. The positive electrode liquid injection structure is used to inject the tracer medium into the positive electrode buffer tank, and the negative electrode liquid injection structure is used to inject the tracer medium into the negative electrode buffer tank; The method of injecting the tracer medium into the positive electrode buffer tank and the negative electrode buffer tank includes at least one of a single or periodic step response method or a pulse response method.

10. The method according to claim 1, characterized in that, Performing image acquisition on the tracer medium in the battery unit to obtain a target image and performing image processing, including: Applying a sheet light source parallel to the flow direction of the mixed medium to the mixed medium in the battery unit at a preset frequency; The sheet light source is used to develop the tracer medium in the mixed medium and form an illuminated flow plane; Performing image acquisition on the flow plane to obtain a target image.

11. The method according to claim 1, wherein Performing kinematic analysis on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the target position of the coupled field and the statistical parameters corresponding to the target motion parameters, including: Obtaining two frames of the target images and determining the acquisition time interval between the two frames of the target images; Performing image processing on each of the target images to obtain an image processing result, and performing correlation analysis on the tracer particles in the respective tracer media corresponding to each of the target images based on the image processing result to obtain the cross-correlation parameters between the tracer particles in each of the target images, the displacement of the tracer particles, and the statistical parameters corresponding to the displacement; Based on the cross-correlation parameters, the displacement, the statistical parameters corresponding to the displacement, and the acquisition time interval, obtaining the target motion parameters of the tracer particles at the target image and the target position of the coupled field and the statistical parameters corresponding to the target motion parameters.

12. The method according to claim 11, wherein The two frames of the target images include a first image and a second image. The first image includes a plurality of first sub-images, and the second image includes a plurality of second sub-images corresponding to the first sub-images; Performing image processing on each of the target images respectively to obtain an image processing result, and performing correlation analysis on the tracer particles in the tracer medium corresponding to each of the target images based on the image processing result to obtain the cross-correlation parameters between the tracer particles in each of the target images, the displacement of the tracer particles, and the statistical parameters corresponding to the displacement, including: Determining an image pair according to the first sub-image and the second sub-image corresponding to the first sub-image, and for each image pair, determining the position correlation between the tracer particles in the tracer medium in the coupled-field target region of each sub-image of the targeted image pair; When the position correlation satisfies the correlation analysis condition, performing Fourier transform on each sub-image of the targeted image pair to obtain the frequency-domain image corresponding to each sub-image of the targeted image pair and the frequency-domain representation of the tracer particles in each frequency-domain image; Based on the frequency-domain representation of the tracer particles in each sub-image, determining the association relationship between the frequency-domain images of the tracer particles; Performing inverse Fourier transform on the frequency-domain image corresponding to each sub-image to obtain the spatial image corresponding to each frequency image; Determining the association parameters of the tracer particles in each sub-image of the targeted image pair according to the spatial image and the association relationship; Based on the association parameters corresponding to each image pair respectively, determining the cross-correlation parameters between the tracer particles in each target image, and determining the displacement between the spatial images of the tracer particles and the statistical parameters corresponding to the displacement.

13. An analysis device for the internal coupled fields of a flow battery stack, wherein the flow battery stack includes battery units and a liquid flow circulation system connected to the battery units; characterized in that, The device includes: A flow control module, configured to determine a preset working state of the flow battery stack, and control the mixed medium in the liquid flow circulation system to flow through the battery unit in the preset working state; the mixed medium includes a tracer medium and a flow battery circulation medium; An image acquisition module, configured to perform image acquisition on the tracer medium in the battery unit during the process of the mixed medium flowing through the internal flow channel of the battery unit to obtain a target image, and perform image processing; An image analysis module, configured to perform kinematic analysis on the image processing result of the tracer medium in the target image to obtain the target motion parameters of the tracer medium at the coupled-field target position and the statistical parameters corresponding to the target motion parameters; the coupled-field target position is the actual spatial position during the process of the mixed medium flowing through the battery unit; A state analysis module, configured to analyze the state of the coupled-field target position according to the target motion parameters and the statistical parameters corresponding to the target motion parameters to obtain a state analysis result of the coupled-field target position; the state analysis result is used to characterize the coupled-field state characteristics and the liquid flow time-varying state characteristics of the coupled-field target position in the flow battery stack.

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