Numerical simulation method and system for flow field of PEM electrolytic cell

Abstract

The invention provides a numerical simulation method of a PEM electrolytic bath flow field, and relates to the technical field of PEM electrolytic baths, the method comprises the following steps: constructing a PEM electrolytic bath three-dimensional model, and meshing the PEM electrolytic bath three-dimensional model; setting a boundary condition, a mass source item, a two-phase flow model and a bubble divergence volume force source item based on the gridded PEM electrolytic cell three-dimensional model, and constructing a PEM electrolytic cell flow field CFD two-phase flow simulation model; and simulating the numerical value of the flow field of the PEM electrolytic cell through the CFD two-phase flow simulation model of the flow field of the PEM electrolytic cell. According to the method, after the three-dimensional model of the PEM electrolytic cell is gridded, the CFD two-phase flow simulation model of the flow field of the PEM electrolytic cell is constructed, and the numerical value of the flow field of the PEM electrolytic cell is simulated through the CFD two-phase flow simulation model of the flow field of the PEM electrolytic cell, so that the calculation complexity is reduced to a great extent.

Description

Technical Field

[0001] The present invention relates to the technical field of PEM electrolyzers, and particularly to a numerical simulation method for the flow field of a PEM electrolyzer; in addition, the present invention also relates to a numerical simulation system for the flow field of a PEM electrolyzer. Background Art

[0002] Proton exchange membrane electrolyzers are an efficient and environmentally friendly hydrolysis technology, which are widely used in fields such as hydrogen production, energy storage, and fuel cells. With the popularization of renewable energy and the development of the hydrogen economy, PEM electrolyzer technology has received increasing attention. However, PEM electrolyzers still face some challenges in practical applications, such as uneven flow distribution, excessive pressure drop, and reduced efficiency.

[0003] To solve these problems, researchers need to deeply study the internal flow characteristics and mass transfer processes of PEM electrolyzers. The simulation method plays an important role in the research of PEM electrolyzers, which can help researchers understand the complex phenomena inside the electrolyzers, optimize the design, and improve the performance. Currently, many simulation models based on computational fluid dynamics are used to study the flow, heat transfer, and mass transfer processes of PEM electrolyzers. However, these models usually have a high computational complexity and require a large amount of computing resources and time. Summary of the Invention

[0004] To solve the problems existing in the prior art, at least one embodiment of the present invention provides a numerical simulation method for the flow field of a PEM electrolyzer, which greatly reduces the computational complexity. For this purpose, at least one embodiment of the present invention also provides a numerical simulation system for the flow field of a PEM electrolyzer.

[0005] In a first aspect, an embodiment of the present invention proposes a numerical simulation method for the flow field of a PEM electrolyzer, including:

[0006] Construct a three-dimensional model of the PEM electrolyzer and mesh the three-dimensional model of the PEM electrolyzer;

[0007] Set boundary conditions, mass source terms, two-phase flow models, and bubble divergence body force source terms based on the meshed three-dimensional model of the PEM electrolyzer, and construct a CFD two-phase flow simulation model for the flow field of the PEM electrolyzer;

[0008] Simulate the numerical value of the flow field of the PEM electrolyzer through the CFD two-phase flow simulation model of the flow field of the PEM electrolyzer.

[0009] In some embodiments, for the numerical simulation method for the flow field of a PEM electrolyzer provided by the present invention, constructing a three-dimensional model of the PEM electrolyzer includes:

[0010] Construct a three-dimensional model of the PEM electrolyzer by the flow field width, flow field height, diffusion layer width, diffusion layer thickness, and proton exchange membrane thickness.

[0011] In some embodiments, for a numerical simulation method of the flow field of a PEM electrolyzer provided by the present invention, the meshing of the three-dimensional model of the PEM electrolyzer includes:

[0012] Perform mesh encryption at the set flow channels of the array bipolar plate flow channels and add a boundary layer to the set flow channels.

[0013] In some embodiments, for a numerical simulation method of the flow field of a PEM electrolyzer provided by the present invention, when setting the boundary conditions, the flow field inlet boundary is set as a velocity inlet boundary, and the velocity value is represented by the following formula 1:

[0014]

[0015] where v in is the inlet flow rate of liquid water, ξ is the liquid water excess coefficient, I is the current density, F is the Faraday constant, is the molar mass of water, A act is the total reaction active area, ρ is the liquid water density, A in is the true area of the flow field inlet.

[0016] In some embodiments, for a numerical simulation method of the flow field of a PEM electrolyzer provided by the present invention, when setting the mass source term, a uniform oxygen and liquid water mass flow rate is set in the array bipolar plate flow channels, and the oxygen mass source term is represented by the following formula 2:

[0017]

[0018] where is the oxygen mass source term, is the molar mass of oxygen, and V is the volume of the bipolar plate flow channels in the three-dimensional model.

[0019] In some embodiments, for a numerical simulation method of the flow field of a PEM electrolyzer provided by the present invention, when setting the two-phase flow model, the double Euler two-phase flow model is adopted, with liquid water set as the primary phase and oxygen set as the secondary phase.

[0020] In some embodiments, for a numerical simulation method of the flow field of a PEM electrolyzer provided by the present invention, when setting the bubble divergence volume force source term, the volume force source term is represented by the following formula 3:

[0021]

[0022] where is the volume force source term, ε gis the gas volume fraction, ρ is the gas density, C D is the drag coefficient, d b is the bubble diameter, U r is the bubble slip velocity, C L is the lift coefficient, K g is the gas diffusion factor, is the liquid flow velocity.

[0023] In a second aspect, an embodiment of the present invention further provides a numerical simulation system for the flow field of a PEM electrolyzer, including:

[0024] A three-dimensional model construction module of the PEM electrolyzer, configured to construct a three-dimensional model of the PEM electrolyzer and mesh the three-dimensional model of the PEM electrolyzer;

[0025] A CFD two-phase flow simulation model construction module of the PEM electrolyzer flow field, configured to set boundary conditions, mass source terms, two-phase flow models, and bubble divergence volume force source terms based on the meshed three-dimensional model of the PEM electrolyzer, and construct a CFD two-phase flow simulation model of the PEM electrolyzer flow field;

[0026] A numerical simulation module, configured to simulate the numerical value of the PEM electrolyzer flow field through the CFD two-phase flow simulation model of the PEM electrolyzer flow field.

[0027] In a third aspect, an embodiment of the present invention further provides a numerical simulation device for the flow field of a PEM electrolyzer, including at least one processor; a memory coupled to the at least one processor, where the memory stores executable instructions, and when the executable instructions are executed by the at least one processor, the steps of any method in the first aspect above are implemented.

[0028] In a fourth aspect, an embodiment of the present invention further provides a chip for executing the steps of the method in the first aspect above. Specifically, the chip includes: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip is used to execute the steps of the method in the first aspect above.

[0029] In a fifth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any method in the first aspect above are implemented.

[0030] It can be seen that a numerical simulation method and system for the flow field of a PEM electrolyzer according to an embodiment of the present invention mesh a three-dimensional model of the PEM electrolyzer and then construct a CFD two-phase flow simulation model of the PEM electrolyzer flow field, and simulate the numerical value of the PEM electrolyzer flow field through the CFD two-phase flow simulation model of the PEM electrolyzer flow field, thereby greatly reducing the computational complexity. Description of the Drawings

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It shows a flowchart of a numerical simulation method for the flow field of a PEM electrolyzer in an embodiment of the present invention;

[0033] Figure 2 It shows a schematic diagram of a three-dimensional model of a PEM electrolyzer in an embodiment of the present invention;

[0034] Figure 3 It shows a distribution diagram of the gas volume fraction in the flow field of a PEM electrolyzer in an embodiment of the present invention;

[0035] Figure 4 It shows a distribution diagram of the mixture velocity in the flow field of a PEM electrolyzer in an embodiment of the present invention;

[0036] Figure 5 It shows a schematic framework diagram of a numerical simulation system for the flow field of a PEM electrolyzer in an embodiment of the present invention. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0038] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In this article, the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitations, the element defined by the statement "including an..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0039]

Example 1

[0040] In the prior art, there have been many simulation models based on computational fluid dynamics for studying the flow, heat transfer, and mass transfer processes in PEM electrolyzers. However, these models generally have a high computational complexity and require a large amount of computational resources and time. The following solution is provided in Example 1 of the present invention:

[0041] As Figures 1 to 4 shown, this embodiment provides a numerical simulation method for the flow field of a PEM electrolyzer, and the method includes the following steps:

[0042] Step 101: Construct a three-dimensional model of the PEM electrolyzer and mesh the three-dimensional model of the PEM electrolyzer.

[0043] In some embodiments, a three-dimensional model of the PEM electrolyzer is constructed by the flow field width, flow field height, diffusion layer width, diffusion layer thickness, and proton exchange membrane thickness.

[0044] In some embodiments, grid encryption is performed at a set flow channel of the array bipolar plate flow channel, and a boundary layer is added to the set flow channel.

[0045] It should be noted that when performing numerical simulation on the array bipolar plate flow channel, the quality and fineness of the grid have an important impact on the accuracy of the simulation results. For the grid type used inside the flow channel, it is a structured grid, such as a rectangular grid, or an unstructured grid, such as a triangular grid. In the boundary layer, a thin layer network is used, such as a quadrilateral or a triangle, so as to better capture the fluid velocity gradient. In the set flow channel, especially in the area near the wall surface, a finer grid is used to improve the simulation accuracy. The method of gradually increasing the density is adopted, and the grid density is gradually increased from the flow channel inlet to the flow channel outlet to avoid numerical instability problems caused by mutations. The grid of the boundary layer unfolds along the wall surface, and the logarithmic method or the geometric series method is used to generate the boundary layer grid. The minimum thickness of the boundary layer should be adapted to the viscous characteristics of the fluid to ensure that the velocity change of the fluid near the wall surface can be accurately captured.

[0046] Step 102: Set the boundary conditions, mass source terms, two-phase flow model, and bubble divergence volume force source terms based on the meshed three-dimensional model of the PEM electrolyzer, and construct a CFD two-phase flow simulation model for the flow field of the PEM electrolyzer.

[0047] In some embodiments, when setting the boundary conditions, the flow field inlet boundary is set as a velocity inlet boundary, and the velocity value is represented by the following formula 1:

[0048]

[0049] where, v inis the inlet flow rate of liquid water, ξ is the liquid water excess coefficient, I is the current density, F is the Faraday constant, is the molar mass of water, A act is the total reactive area, ρ is the liquid water density, A in is the true area of the flow field inlet.

[0050] In some embodiments, when setting the mass source term, a uniform mass flow rate of oxygen and liquid water is set in the flow channels of the array bipolar plates. The mass source term of oxygen is expressed by Equation 2 below:

[0051]

[0052] Wherein, is the mass source term of oxygen, is the molar mass of oxygen, V is the volume of the bipolar plate flow channel in the three-dimensional model.

[0053] In some embodiments, when setting the two-phase flow model, a dual Euler two-phase flow model is adopted, with liquid water set as the primary phase and oxygen set as the secondary phase.

[0054] In some embodiments, when setting the bubble divergence volume force source term, the volume force source term is expressed by Equation 3 below:

[0055]

[0056] Wherein, is the volume force source term, ε g is the gas volume fraction, ρ is the gas density, C D is the drag coefficient, d b is the bubble diameter, U r is the bubble slip velocity, C L is the lift coefficient, K g is the gas diffusion factor, is the liquid flow velocity.

[0057] Step 103, numerically simulate the PEM electrolyzer flow field through the PEM electrolyzer flow field CFD two-phase flow simulation model.

[0058]

Embodiment 2

[0059] As Figure 5 shown, this embodiment provides a face wrinkle segmentation system based on Swin-Transformer, including

[0060] A PEM electrolyzer three-dimensional model construction module 201 for constructing a PEM electrolyzer three-dimensional model and meshing the PEM electrolyzer three-dimensional model.

[0061] In some embodiments, a three-dimensional model of the PEM electrolyzer is constructed by the flow field width, flow field height, diffusion layer width, diffusion layer thickness, and proton exchange membrane thickness.

[0062] In some embodiments, grid encryption is performed at the set flow channels of the array bipolar plate flow channels, and a boundary layer is added to the set flow channels.

[0063] It should be noted that when performing numerical simulation of the array bipolar plate flow channels, the quality and fineness of the grid have an important impact on the accuracy of the simulation results. For the grid type used inside the flow channels, structured grids such as rectangular grids or unstructured grids such as triangular grids are employed. In the boundary layer, thin layer grids such as quadrilaterals or triangles are used to better capture the fluid velocity gradient. In the set flow channels, especially in the region close to the wall, finer grids are used to improve the simulation accuracy. The method of gradually increasing the grid density is adopted, gradually increasing the grid density from the flow channel inlet to the flow channel outlet to avoid numerical instability problems caused by sudden changes. The grids in the boundary layer are expanded along the wall, and the logarithmic method or geometric series method is used to generate the boundary layer grids. The minimum thickness of the boundary layer should be adapted to the viscous characteristics of the fluid to ensure that the velocity change of the fluid near the wall can be accurately captured.

[0064] The PEM electrolyzer flow field CFD two-phase flow simulation model construction module 202 is used to set the boundary conditions, mass source terms, two-phase flow model, and bubble divergence volume force source terms based on the meshed three-dimensional model of the PEM electrolyzer, and construct the PEM electrolyzer flow field CFD two-phase flow simulation model.

[0065] In some embodiments, when setting the boundary conditions, the flow field inlet boundary is set as a velocity inlet boundary, and the velocity value is expressed as the following formula 1:

[0066]

[0067] Where, v in is the liquid water inlet flow rate, ξ is the liquid water excess coefficient, I is the current density, F is the Faraday constant, is the molar mass of water, A act is the total reactive area, ρ is the liquid water density, A in is the true area of the flow field inlet.

[0068] In some embodiments, when setting the mass source terms, uniform oxygen and liquid water mass flow rates are set in the array bipolar plate flow channels, and the oxygen mass source term is expressed as the following formula 2:

[0069]

[0070] Where, is the oxygen mass source term, is the molar mass of oxygen, and V is the volume of the bipolar plate flow channel in the three-dimensional model.

[0071] In some embodiments, when setting up the two-phase flow model, the two-fluid Eulerian two-phase flow model is adopted, with liquid water set as the primary phase and oxygen set as the secondary phase.

[0072] In some embodiments, when setting up the bubble divergence volume force source term, the volume force source term is represented by Equation 3 below:

[0073]

[0074] Where, is the volume force source term, ε g is the gas volume fraction, ρ is the gas density, C D is the drag coefficient, d b is the bubble diameter, U r is the bubble slip velocity, C L is the lift coefficient, K g is the gas diffusion factor, is the liquid flow velocity.

[0075] The numerical simulation module 203 is used to simulate the numerical values of the PEM electrolyzer flow field through the CFD two-phase flow simulation model of the PEM electrolyzer flow field.

[0076]

Embodiment 3

[0077] This embodiment provides a numerical simulation device for the PEM electrolyzer flow field, including:

[0078] At least one processor; a memory coupled to the at least one processor, the memory storing executable instructions, wherein the executable instructions, when executed by the at least one processor, cause the method steps of Embodiment 1 of the present invention to be implemented.

[0079] For the numerical simulation device of the PEM electrolyzer flow field provided by the embodiments of the present invention, the processor and the memory can be set separately or integrated together.

[0080] For example, the memory may include random access memory, flash memory, read-only memory, programmable read-only memory, non-volatile memory, or registers, etc. The processor may be a central processing unit (CPU), etc. Or a graphic processing unit (GPU). The memory can store executable instructions. The processor can execute the executable instructions stored in the memory, thereby implementing the various processes described herein.

[0081] It can be understood that the memory in this embodiment can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), EEPROM (Electrically EPROM), or flash memory. The volatile memory can be RAM (Random Access Memory), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as SRAM (Static RAM), DRAM (Dynamic RAM), SDRAM (Synchronous DRAM), DDR SDRAM (Double Data Rate SDRAM), ESDRAM (Enhanced SDRAM), SLDRAM (Synchlink DRAM), and DRRAM (Direct Rambus RAM). The memory described herein is intended to include but not be limited to these and any other suitable types of memory.

[0082] In some embodiments, the memory stores the following elements, an upgrade package, an executable unit, or a data structure, or a subset thereof, or an extended set thereof: an operating system and an application program.

[0083] Among them, the operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application program includes various application programs for implementing various application services. The program for implementing the method of the embodiment of the present invention can be included in the application program.

[0084] In the embodiment of the present invention, the processor calls the program or instruction stored in the memory, specifically, the program or instruction stored in the application program, and the processor is used to execute the method steps of Embodiment 1 of the present invention.

[0085]

Embodiment 4

[0086] This embodiment provides a chip for implementing the method of Embodiment 1 of the present invention. Specifically, the chip includes a processor configured to call and run a computer program from a memory, such that a device installed with the chip is used to implement the method of Embodiment 1 of the present invention.

[0087]

Embodiment 5

[0088] This embodiment provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method of Embodiment 1 of the present invention are implemented.

[0089] For example, the machine-readable storage medium may include, but is not limited to, various known and unknown types of non-volatile memories.

[0090] In summary, Embodiments 1-5 of the present invention provide a numerical simulation method and system for a PEM electrolyzer flow field. After meshing a three-dimensional model of the PEM electrolyzer, a CFD two-phase flow simulation model of the PEM electrolyzer flow field is constructed, and the numerical values of the PEM electrolyzer flow field are simulated through the CFD two-phase flow simulation model of the PEM electrolyzer flow field, thereby greatly reducing the computational complexity.

[0091] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0092] In the embodiments of the present application, the disclosed systems, devices, and methods can be implemented in other ways. For example, the division of units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system. Additionally, the coupling between each unit can be direct or indirect. Further, in the embodiments of the present application, each functional unit can be integrated in a processing unit, or can exist separately physically, etc.

[0093] It should be understood that in various embodiments of the present application, the magnitudes of the sequence numbers of the various processes do not mean the order of execution, and the order of execution of the various processes should be determined by their functions and internal logics, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0094] When the above-described functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a machine-readable storage medium. Therefore, the technical solution of this application can be embodied in the form of a software product, which can be stored in a machine-readable storage medium and may include several instructions to enable an electronic device to execute all or part of the processes of the technical solution described in the embodiments of this application. The above storage medium may include various media that can store program codes, such as ROM, RAM, removable disks, hard disks, magnetic disks, or optical discs.

[0095] The above content is only the specific implementation manner of this application, and the protection scope of this application is not limited thereto. Those skilled in the art can make changes or substitutions within the technical scope disclosed in this application, and these changes or substitutions should be within the protection scope of this application.

Claims

1. A numerical simulation method for a PEM electrolyzer flow field, characterized in that: include: Constructing a three-dimensional model of a PEM electrolyzer and meshing the three-dimensional model of the PEM electrolyzer; Based on the gridded three-dimensional model of the PEM electrolyzer, the boundary conditions, mass source terms, two-phase flow model and bubble divergence volume force source terms are set, and a CFD two-phase flow simulation model of the PEM electrolyzer flow field is constructed; The PEM electrolyzer flow field CFD two-phase flow simulation model is used to numerically simulate the PEM electrolyzer flow field.

2. The numerical simulation method of the PEM electrolyzer flow field according to claim 1, characterized in that: The constructing of the three-dimensional model of the PEM electrolyzer comprises: The three-dimensional model of the PEM electrolyzer is constructed by flow field width, flow field height, diffusion layer width, diffusion layer thickness and proton exchange membrane thickness.

3. The numerical simulation method of the PEM electrolyzer flow field according to claim 1, characterized in that: The meshing of the three-dimensional model of the PEM electrolyzer comprises: The grid is encrypted at the set flow channel of the array bipolar plate flow channel, and a boundary layer is added to the set flow channel.

4. The numerical simulation method of the flow field of a PEM electrolyzer according to claim 1, characterized in that: When setting the boundary conditions, the flow field inlet boundary is set as the velocity inlet boundary, and the velocity value is expressed as follows: Among them, v in is the liquid water inlet velocity, ξ is the liquid water excess coefficient, I is the current density, F is the Faraday constant, is the molar mass of water, A act is the total reactive area, ρ is the density of liquid water, A in is the actual area of ​​the flow field inlet.

5. The numerical simulation method of the flow field of a PEM electrolyzer according to claim 1, characterized in that: When setting the mass source term, a uniform mass flow rate of oxygen and liquid water is set in the flow channel of the array bipolar plate. The mass source term of oxygen is expressed as follows: in, is the mass source term of oxygen, is the molar mass of oxygen, and V is the volume of the bipolar plate flow channel in the three-dimensional model.

6. The numerical simulation method of the flow field of a PEM electrolyzer according to claim 1, characterized in that: When setting the two-phase flow model, a dual-Euler two-phase flow model is adopted, liquid water is set as the main phase and oxygen is set as the secondary phase.

7. The numerical simulation method based on the flow field of a PEM electrolyzer according to claim 1, characterized in that: When the bubble divergence volume force source term is set, the volume force source term is expressed by the following formula 3: in, is the body force source term, ε g is the gas volume fraction, ρ is the gas density, C D is the drag coefficient, d b is the bubble diameter, U r is the bubble slip velocity, C L is the lift coefficient, K g is the gas diffusion factor, is the liquid flow rate.

8. A numerical simulation system for flow field of a PEM electrolyzer, characterized in that: include: A PEM electrolyzer three-dimensional model building module, used to build a PEM electrolyzer three-dimensional model and grid the PEM electrolyzer three-dimensional model; The PEM electrolyzer flow field CFD two-phase flow simulation model construction module is used to set the boundary conditions, mass source terms, two-phase flow model and bubble divergence volume force source terms based on the gridded PEM electrolyzer three-dimensional model, and to construct the PEM electrolyzer flow field CFD two-phase flow simulation model; The numerical simulation module is used to simulate the numerical value of the PEM electrolyzer flow field through the PEM electrolyzer flow field CFD two-phase flow simulation model.

9. A numerical simulation device for a PEM electrolyzer flow field, comprising at least one processor; a memory coupled to the at least one processor, the memory storing executable instructions, characterized in that: The executable instructions, when executed by the at least one processor, enable the steps of the method according to any one of claims 1 to 7 to be implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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