Simulation modeling method for multiple physical fields of electrolytic cell, electrolytic cell system and application

Abstract

The invention provides an electrolytic bath multi-physical field simulation modeling method, an electrolytic bath system and application. The method comprises the steps that geometric parameters and physical parameters of an electrolytic bath are obtained; establishing a three-dimensional geometric model of the electrolytic cell based on the geometric parameters; based on the physical parameters, the electrolyte, the electrochemical reaction and the reaction product, an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model and a gravitational effect model of the electrolytic cell are established, and analogue simulation is completed through coupling; the electrochemical model adopts secondary current distribution; the two-phase flow model is used for simulating electrolyte convection caused by bubbles and turbulent flow caused by the fact that electrolyte enters an electrolytic bath through an inlet pipeline; the concentration field model is used for simulating diffusion and convective transportation; the temperature field model is used for simulating conduction heat transfer and convective heat transfer; the gravitational effect model is used for simulating flow of bubbles and electrolyte under the gravitational effect. According to the scheme, refined simulation of the electrolytic cell is realized, each physical field of the electrolytic cell can be accurately simulated, and a reliable basis is provided for technological parameter optimization.

Description

Technical Field

[0001] This invention relates to the field of electrolytic cell technology, and in particular to a simulation modeling method for multiphysics fields in electrolytic cells, an electrolytic cell system, and its applications. Background Technology

[0002] An electrolytic cell is a device used in electrolysis processes, playing a crucial role in modern industrial production and energy conversion. It is widely used in metal electrolysis, electroplating, electrolytic refining, and battery manufacturing. Based on different technological characteristics and application ranges, electrolytic cells can be classified into four types: alkaline electrolytic cells (ALK), proton exchange membrane electrolytic cells (PEM), anion exchange membrane electrolytic cells (AEM), and solid oxide electrolytic cells (SOEC). An electrolytic cell consists of a tank body, an anode, and a cathode, with most separating the anode and cathode chambers using a diaphragm.

[0003] An electrolytic cell system is a complex dynamic system, constrained and limited by input conditions and operating parameters, and involves the interaction of multiple physical fields. These fields are coupled and mutually influential, jointly determining the electrolytic cell's performance and product quality. Currently, most electrolytic cell simulation studies employ only two- or three-field coupling methods. While this simplified simulation method reduces computational complexity to some extent, it cannot accurately reflect the actual physicochemical processes within the electrolytic cell. The lack of simulation of some physical fields makes it impossible to accurately predict the flow states of the gas and liquid phases within the electrolytic cell, leading to insufficient understanding of the mass transport process on the electrode surface. This, in turn, affects the prediction of current efficiency and product quality, failing to provide a reliable basis for process parameter optimization and failing to meet the high-precision simulation requirements of industrial production. Therefore, there is an urgent need to develop a multi-physics simulation modeling method for electrolytic cells, as well as an electrolytic cell system and its applications. Summary of the Invention

[0004] This invention provides a simulation modeling method for multiphysics fields in electrolytic cells, an electrolytic cell system, and its application. It achieves refined simulation of electrolytic cells, accurately simulates various physical fields in the electrolytic cell, and provides a reliable basis for optimizing process parameters.

[0005] In a first aspect, the present invention provides a simulation modeling method for multiphysics fields in an electrolytic cell, comprising:

[0006] Obtain the geometric and physical parameters of the electrolytic cell;

[0007] A three-dimensional geometric model of the electrolytic cell is established based on the geometric parameters;

[0008] Based on the physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational effect model of the electrolytic cell are established, and simulation is performed through coupling. The electrochemical model employs a secondary current distribution; the two-phase flow model simulates electrolyte convection caused by bubbles and turbulence caused by electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model simulates diffusion and convective transport; the temperature field model simulates conductive and convective heat transfer; and the gravitational effect model simulates the flow of bubbles and electrolyte under gravitational influence.

[0009] Secondly, the present invention provides a simulation modeling device for multiphysics fields in an electrolytic cell, comprising:

[0010] The acquisition module is used to acquire the geometric and physical parameters of the electrolytic cell;

[0011] A construction module is used to establish a three-dimensional geometric model of the electrolytic cell based on the geometric parameters; based on the physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational effect model of the electrolytic cell are established, and simulation is completed through coupling; wherein, the electrochemical model adopts a secondary current distribution; the two-phase flow model is used to simulate electrolyte convection caused by bubbles and turbulence caused by electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model is used to simulate diffusion and convective transport; the temperature field model is used to simulate conductive heat transfer and convective heat transfer; and the gravitational effect model is used to simulate the flow of bubbles and electrolyte under the action of gravity.

[0012] Thirdly, embodiments of the present invention also provide a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any of the first aspects of this specification.

[0013] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any of the first aspects of this specification.

[0014] Fifthly, embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in any of the first aspects of this specification.

[0015] In a sixth aspect, embodiments of the present invention also provide an electrolytic cell system, comprising: a cathode plate and an anode plate located at both ends of the electrolytic cell, and a diaphragm located between the cathode plate and the anode plate, and an electrolyte located within the electrolytic cell; both the cathode plate and the anode plate are circular; the cathode plate is composed of a plurality of mutually independent cathode sheets.

[0016] Seventhly, embodiments of the present invention also provide an application of a simulation modeling method for multiphysics fields in an electrolytic cell, used to analyze the working characteristics of the electrolytic cell under target operating conditions or to monitor the current value passing through the cathode plate.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] This invention provides a simulation modeling method for multiple physics fields in an electrolytic cell. It establishes an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational field model for the electrolytic cell. This enables the simulation of multiple physics fields in the electrolytic cell, achieving refined simulation while providing a reliable basis for optimizing process parameters.

[0019] The electrolytic cell system provided by this invention enables precise monitoring of the local current distribution at the cathode. Furthermore, simulation modeling methods can be used to further analyze the operating characteristics of the electrolytic cell under target conditions or monitor the current value passing through the cathode plate, thus providing a reliable basis for optimizing the operating parameters of the electrolytic cell and improving its efficiency. Moreover, by comparing the local current distribution at the cathode obtained by this electrolytic cell system with the current value of the cathode plate obtained through simulation modeling, the accuracy of the simulation modeling method is further verified. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a simulation modeling method for multiphysics fields in an electrolytic cell provided by an embodiment of the present invention;

[0022] Figure 2 This is a cathode plate provided in one embodiment of the present invention;

[0023] Figure 3 This is an exploded view of the components of an electrolytic cell system provided in an embodiment of the present invention;

[0024] Figure 4 This is an electrolytic cell system provided in one embodiment of the present invention;

[0025] Figure 5 This is a comparison chart of experimental and simulated data of average current density provided in an embodiment of the present invention;

[0026] Figure 6 This is a graph showing the variation of current density on the xz plane with the z-axis, provided by an embodiment of the present invention.

[0027] Figure 7 This is a cloud map of simulated local current density data of a cathode plate provided in an embodiment of the present invention;

[0028] Figure 8 This is a cloud map of experimental data on the local current density of a cathode plate provided in an embodiment of the present invention;

[0029] Figure 9 This is a hardware architecture diagram of a computing device provided in an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of the structure of a simulation modeling device for multiphysics fields in an electrolytic cell according to an embodiment of the present invention;

[0031] Reference numerals: 301-Cathode side end plate, 302-Cathode plate, 303-Gasket, 304-Electrolyte flow channel, 305-Diaphragm clamp, 306-Diaphragm, 307-Anode plate, 308-Anode side end plate. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The following describes the specific implementation of the concept in this application.

[0034] Please refer to Figure 1 This invention provides a simulation modeling method for multiphysics fields in an electrolytic cell, the method comprising:

[0035] Step 100: Obtain the geometric and physical parameters of the electrolytic cell;

[0036] Step 102: Establish a three-dimensional geometric model of the electrolytic cell based on the geometric parameters;

[0037] Step 104: Based on physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, establish the electrochemical model, two-phase flow model, concentration field model, temperature field model, and gravitational effect model of the electrolytic cell, and complete the simulation through coupling. Among them, the electrochemical model adopts a secondary current distribution; the two-phase flow model is used to simulate the electrolyte convection caused by bubbles and the turbulence caused by the electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model is used to simulate diffusion and convective transport; the temperature field model is used to simulate conductive heat transfer and convective heat transfer; and the gravitational effect model is used to simulate the flow of bubbles and electrolyte under the action of gravity.

[0038] In this embodiment of the invention, by establishing an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational field model of the electrolyzer, multi-physics field coupling of electric field, flow field, concentration field, temperature field, and gravitational effect is carried out. This achieves refined simulation and provides a reliable basis for optimizing process parameters, significantly improving the accuracy and engineering applicability of traditional models.

[0039] The following description Figure 1 The execution method for each step is shown.

[0040] In this embodiment of the invention, in order to improve the computational convergence of the multiphysics coupling model of the alkaline electrolyzer and reduce the computational cost, the following assumptions are made:

[0041] a: Ignore the differences between the electrolysis chambers of the electrolytic cell;

[0042] b: Ignore the exchange of gases produced by the electrochemical reaction through the membrane;

[0043] c: Ignore complex reactions and assume Faraday efficiency is 100%;

[0044] d: The gaseous substances in the electrolytic cell are gases produced by electrochemical reactions and vapors formed by molecules volatilized from the electrolyte;

[0045] e: The input voltage of the electrolytic cell is a stable voltage, and fluctuating power is not considered.

[0046] For step 100, the geometric parameters include, but are not limited to, the geometric parameters of each component of the electrolytic cell, the electrode spacing, the electrode structure, the diaphragm structure (including the diaphragm thickness and porosity), and the flow channel layout (including the diameter of the electrolyte inlet pipe and the diameter of the electrolyte outlet pipe, etc.); the physical parameters include, but are not limited to, the electrical conductivity, thermal conductivity, specific heat capacity, and electrode kinetic parameters of the electrolyte and the electrode.

[0047] Specifically, the three-dimensional geometric model mainly includes the cathode chamber, anode chamber, diaphragm, cathode plate, and anode plate. Preferably, the three-dimensional geometric model is used to reproduce the electrolytic cell dimensions at a 1:1 scale. Simultaneously, a free tetrahedral mesh is used to divide the three-dimensional geometric model according to the characteristics of each physical field.

[0048] Regarding step 104, in a preferred embodiment, the electrochemical model includes:

[0049]

[0050] Among them, E eq E is the equilibrium voltage (V); T is the temperature (K); E is the equilibrium voltage (V); T is the temperature (K); E is the equilibrium voltage (V); T is the temperature (K); E is the equilibrium voltage (V); E is the temperature (K ... eq,ref (T) is the reference equilibrium voltage (V) at temperature T; R is the universal gas constant [J / (mol·K)]; n is the number of participating electrons; F is the Faraday constant (C / mol); P i For species pressure; v i i is the stoichiometric coefficient; loc,expr Local current density at the cathode or anode (A / m) 2 i0 is the exchange current density (A / m). 2 ); η is the overpotential, which refers to the difference between the actual working potential of the electrode and the equilibrium potential; α a α is the anodic reaction transfer coefficient; c is the cathode reaction transfer coefficient.

[0051] Specifically, the secondary current distribution considers not only the electrode resistance but also the activation polarization generated by the electrochemical reaction, that is, the electrode reaction kinetics are considered to have a finite rate, and a nonlinear charge conservation equation is adopted. The equilibrium voltage is calculated by the Nernst equation, as shown in formula (1); the chemical reaction kinetics describes the current density caused by the electrochemical reaction as a function of the overpotential, reactant and product concentrations, and the general Butler-Volmer equation (i.e., formula (2)) is used to describe the process. The anodic reaction transfer coefficient and the cathode reaction transfer coefficient are obtained by experimentally fitting the electrode kinetic parameters.

[0052] In a preferred embodiment, the two-phase flow model employs the mass conservation equation, momentum balance equation, turbulence equation, and bubble dispersion equation;

[0053] The mass conservation equations include:

[0054]

[0055] Among them, u c The velocity of the liquid phase in the electrolytic cell (m / s); u d The velocity of the gas phase within the electrolytic cell (m / s); φ d φ is the gas phase volume fraction. c The volume fraction of the liquid phase; m dc The mass transfer rate from gas to liquid [kg / (m³)] 3 ·s)];ρ c ρ dDensities of the liquid phase and gas phase (kg / m³) respectively 3 );D md μ is the turbulence dispersion coefficient. T σ is the turbulent viscosity; T For turbulent Schmidt number;

[0056] The momentum balance equations include:

[0057]

[0058] Where p is the mixing pressure (Pa); I is the identity matrix; τ c τ d ρ represents the viscous stress tensor (Pa) of the liquid phase and the gas phase, respectively; g represents the acceleration due to gravity (m). 2 / s); F m,c F m,d Interphase momentum transfer phases (N / m) of liquid and gas phases respectively 3 );F c F m,d Other volume forces (N / m) related to the liquid and gas phases, respectively. 3 );u int The phase velocity is φ (m / s). d φ is the gas phase volume fraction. c It represents the liquid phase volume fraction;

[0059] Turbulence equations include:

[0060]

[0061]

[0062] Among them, u m The mass-average mixing velocity (m / s); μ is the viscosity; σ k C ε,1 C ε,2 C μ These are the standard k-ε model constants; k is the turbulent kinetic energy; and ε is the kinetic energy dissipation rate.

[0063] The bubble dispersion equations include:

[0064]

[0065] in, For the volumetric force of bubble dispersion; K g d is the gas phase dispersion coefficient; b U is the bubble diameter (m); r The sliding velocity is φ (m / s). d ρ is the gas phase volume fraction; c ρ is the density of the liquid phase.

[0066] Specifically, the electrolyte convection caused by bubbles generated from gaseous reaction products in the electrolysis chamber and the turbulence caused by the electrolyte entering the electrolysis cell through the inlet pipe are considered. The Euler-Euler (turbulence) model is used to solve for the velocity vectors and gas volume fractions of the gas and liquid phases. Since the liquid phase and the gaseous reaction product phase in the electrolysis cell each correspond to a velocity field, two sets of Navier-Stokes equations need to be solved. The dynamic processes of each phase can be described by the mass conservation equation and the momentum balance equation. The continuity equation is expressed as formula (3), the gas phase transport equation is expressed as formulas (4) and (5), and the momentum conservation equations for the liquid and gas phases are expressed as formulas (6) and (7). At the same time, the flow of the electrolyte and the gas phase distribution are analyzed by coupling the k-ε model with the Euler-Euler model. The expressions for the turbulent kinetic energy k and the kinetic energy dissipation rate ε of the electrolysis cell flow field are shown in formulas (8) to (11), and ρ is related to u m The density of the corresponding mixed phase. In addition, since high concentration of bubbles increases bubble collisions, thereby triggering the diffusion of bubbles from high concentration to low concentration, a bubble dispersion term is also introduced into the volume force, expressed as Equation (12).

[0067] In a preferred embodiment, the concentration field model includes:

[0068]

[0069] Among them, J i Mass diffusion flux [mol / (m 2 ·s)]; u is the mass-average velocity (m / s); C i Species concentration (mol / m 3 ); R i The reaction rate of the species [mol / (m 3 ·s)];

[0070] The concentration field model also includes setting flux boundary conditions by coupling the electrode surface:

[0071]

[0072] Where m represents the reaction at the electrode-electrolyte interface; v i i is the stoichiometric coefficient; loc R is the local current density; F is the Faraday constant; R i,m R represents the rate of the m-th reaction at the electrode-electrolyte interface in which component i participates; i Let be the electrode reaction rate of component i, i.e., the mass flux rate.

[0073] In a preferred embodiment, the temperature field model includes:

[0074]

[0075] Among them, C p Q is the constant-pressure molar heat capacity of the electrolytic cell; K is the thermal conductivity; Q h Q is the total heat source; JH The pyrogen term for the Joule heating of the electrodes and electrolytes; Q m Q is a local heat source generated by an electrochemical reaction process; b,tot The total heat source generated by the electrochemical reaction on the electrode surface; a v,m Specific surface area (m²) 2 / m 3 ); For temperature gradient; ρ c The density of the liquid phase; u c φ represents the velocity of the liquid phase within the electrolytic cell, i.e., the velocity of the electrolyte. s The potential of the electrode phase; φ l The potential of the electrolyte phase; i s i is the current density of the electrode phase; l K represents the current density in the electrolyte phase. Specifically, K represents the thermal conductivity of the electrolyte; E... eq,m i is the equilibrium voltage of the m-th reaction at the electrode-electrolyte interface; loc,m Let be the local current density of the m-th reaction at the electrode-electrolyte interface; T is the temperature.

[0076] Specifically, charge transport in the electrolyte, charge transport in the electrode, and activation overpotential in the electrode reaction are all heat sources, which are simulated by conduction and convection heat transfer. The energy conservation equation based on the partial differential equation is shown in formula (16); the sum of Joule heating and electrochemical sources is the total heat source, as shown in formula (17); Joule heat caused by charge transport, when charged particles are transported in the electric field, electrical energy is converted into heat energy, and the heat source term of Joule heat in the electrode and electrolyte phase is shown in formula (18); the local heat source generated by the electrochemical reaction process is shown in formula (19), where the first three terms in parentheses represent irreversible activation loss, and the fourth term is the reversible thermal change generated during the conversion process; the total heat source Q generated by the electrochemical reaction on the electrode surface is shown in formula (19). b,tot It is the sum of all individual heat sources of the electrode reaction, as shown in Equation (20).

[0077] It should be noted that in the above formula... • Both represent divergence operations.

[0078] In a preferred embodiment, the simulation is performed through coupling within a three-dimensional geometric model, including:

[0079] To address the coupling of the electrochemical model and the two-phase flow model, the gas-phase mass flow rate and liquid-phase mass flow rate generated by the reaction are calculated using the flux of the reactants on the electrode surface as the boundary conditions of the flow field. The flux caused by the electrode reaction is the molecular flux of the reactants reaching or leaving the electrode surface due to the electrode reaction. By using Faraday's law, the flux of the reactants on the boundary is coupled to the electrode reaction current density, as expressed by equation (21):

[0080]

[0081]

[0082] m liquid =-m gas (twenty three)

[0083] In the formula, taking the electrolytic hydrogen production process as an example, the electrolyte is an aqueous solution of KOH; j represents the gas phase, namely hydrogen and oxygen; m gas N is the gas phase mass flow rate; j V represents the molecular flux of the gas phase, indicating the amount of gaseous phase j passing through a unit area of ​​electrode plate surface per unit time; jm i is the stoichiometric coefficient of species j in the m-th reaction at the electrode-electrolyte interface; m n represents the local current density of the m-th reaction at the electrode-electrolyte interface; m is the number of electrons transferred in the m-th reaction at the electrode-electrolyte interface; F is the Faraday constant; This refers to the electrolyte evaporation rate, specifically the water evaporation rate. M is the molar mass of water; j m is the molar mass of the gas phase; liquid This is the liquid phase mass flow rate.

[0084] In this embodiment of the invention, the coupling effect between the flow field and the electric field is crucial for the dynamic feedback of the concentration field. The flow field, through its velocity field, influences the mass transport within the concentration field. The velocity obtained from the flow field solution is substituted into formula (13) to obtain the convective transport in the concentration field. The local current density at the electrode reaction interface, calculated using the electrochemical model, defines the gas-phase flux boundary conditions in the concentration field. These dynamic feedbacks foster a complex interaction between various factors, including the gas generation rate of the electrolyzer, current density, electrolyte concentration, and flow field velocity.

[0085] In this embodiment of the invention, the current obtained from the electrochemical model is used to calculate the Joule heat generated by charge transport and the exothermic reaction in the temperature field. During the operation of the electrolytic cell, the rate of heat generation is proportional to the reaction rate. This heat is transferred through heat conduction and heat convection, affecting the overall temperature distribution of the electrolytic cell. Simultaneously, temperature changes directly affect the electrolytic reaction rate in the electrolytic cell, and also influence the viscosity, mass transfer diffusion coefficient, and conductivity of the electrolyte in the electrolyte solution through the thermophysical property functions set in the model, thereby affecting bubble movement and concentration field distribution.

[0086] In a preferred embodiment, the electrode kinetic parameters, electrolyte conductivity, effective electrolyte conductivity in the membrane, and effective electrolyte conductivity in the electrolyte chamber are used as electrode reaction boundaries in the electrochemical model.

[0087] The two-phase flow model uses the gas phase mass flow rate and the liquid phase mass flow rate as the boundary conditions of the flow field.

[0088] In a specific embodiment, taking an alkaline electrolyzer for hydrogen production as an example, the reaction products include hydrogen and oxygen, and the electrolyte is a KOH aqueous solution. The physical parameters of this electrolyzer are set according to actual operating conditions. Specifically, for the electrochemical model, an electronically conductive phase, an electrolyte phase, a membrane, a hydrogen phase, and an oxygen phase are defined respectively. In the electronically conductive phase, the anode potential is set to the electrolyzer's operating voltage, and the cathode voltage is set to ground. Electrode reaction boundaries are set with electrode kinetic parameters (obtained through electrochemical measurements using a three-electrode system electrochemical workstation), and the electrolyte conductivity is input. The effective electrolyte conductivity in the membrane node is defined as the electrolyte conductivity multiplied by a correction factor; using Bruggeman, the electrolyte volume fraction is input as the membrane porosity. Similarly, the effective electrolyte conductivity in the hydrogen (oxygen)-electrolyte chamber node is set using the same method. Finally, the boundaries of other walls of the electrolyzer are defined as being in an insulated state.

[0089] For the two-phase flow model, the electrolyte flow in the cathode and anode chambers of the electrolyzer is defined separately. First, gravity is set; then, according to Faraday's law, the molar flux of the species perpendicular to the electrode-electrolyte interface is obtained, and the gas and liquid mass flow rates generated by the reaction are derived as flow field boundary conditions. Electrolyte inflow velocities are set at the inlets of the cathode and anode chambers. Outlet pressure values ​​are set at the electrolyzer outlet. Considering the bubble dispersion force, volume forces are added and relevant formulas are input. Finally, no-slip boundary conditions are defined on the remaining wall boundaries.

[0090] For the concentration field model, the mass transfer processes within the cathode and anode chambers are defined. First, the concentration of the KOH aqueous solution flowing into the electrolyte inlet is set. The electrolyte convection velocity is defined as the liquid phase flow velocity in the two-phase flow model. Gas-related parameters on the electrode surface are defined according to Faraday's law. Coupled nodes are added to the electrode surface, and reaction coefficients are set based on the alkaline water electrolysis reaction equation.

[0091] For the temperature field model, the temperature transfer process within each domain is defined. First, the specific heat capacity and thermal conductivity of the KOH aqueous solution are set. Temperature boundary conditions are set at the electrolyte inlet, and the outflow boundary is defined. An electrochemical reaction boundary heat source is set as the heat source, and thermal insulation is defined for the remaining walls. Multiphysics nodes are added to couple the water electrolyzer and heat transfer interface.

[0092] The present invention also provides an electrolytic cell system, comprising: a cathode plate and an anode plate located at both ends of the electrolytic cell and a diaphragm located between the cathode plate and the anode plate, and an electrolyte located within the electrolytic cell; both the cathode plate and the anode plate are circular; the cathode plate is composed of several independent cathode sheets.

[0093] In this embodiment of the invention, the cathode plate is composed of several independent cathode sheets rather than a single integral cathode sheet. This enables the simulation of the physical field of each local area on the cathode plate, achieving accurate simulation of each area.

[0094] In a preferred embodiment, such as Figure 2 As shown, the cathode plate consists of 92 mutually insulated cathode sheets. The machining error of each cathode sheet ranges from -0.03 mm to 0 mm. For the cathode sheets at the edges, their area must be at least 40% of the area of ​​the cathode sheets at the center.

[0095] In a preferred embodiment, such as Figure 3 and Figure 4 As shown, the electrolytic cell includes a cathode side end plate 301, a cathode plate 302, a gasket 303, an electrolyte flow channel 304, a gasket 303, a diaphragm clamping plate 305, a diaphragm 306, a diaphragm clamping plate 305, a gasket 303, an electrolyte flow channel 304, a gasket 303, an anode plate 307, and an anode side end plate 308 connected in sequence; wherein, the electrolyte flow channel 304 is provided with an electrolyte inlet and an electrolyte outlet.

[0096] Specifically, the various components in the electrolytic cell are assembled by fastening with bolts.

[0097] The present invention also provides an application of a multiphysics simulation modeling method for electrolytic cells, which is used to analyze the working characteristics of electrolytic cells under target operating conditions or to monitor the current value passing through the cathode plate.

[0098] In one specific implementation, such as Figure 2The circular cathode plate shown is prepared by the following method:

[0099] S1: The electrode material is cut into sections using a wire cutting method, such as... Figure 2 The diagram shows 92 cathode plates, and the sum of the areas of all the cathode plates is approximately equal to the total area of ​​the cathode plate.

[0100] S2: Using 3D printing technology, a support component is made using photosensitive resin material. The support component can insulate between adjacent cathode plates.

[0101] S3: One cathode plate is soldered to one wire using a soldering method, for a total of 92 soldering operations;

[0102] S4: Measure the total resistance of each cathode plate and its wires using a ohmmeter to ensure that the resistance of each cathode plate and its wires is within ±0.75 milliohms of the average resistance of all measured resistances, thereby minimizing current error.

[0103] S5: Seal one side of the support member with a layer of aluminum foil tape in step S2;

[0104] S6: Assemble the cathode sheet welded in step S4 into the photosensitive resin support, ensuring that the bottom of the photosensitive resin and the bottom of each cathode sheet are on the same plane.

[0105] S7: Pour epoxy resin into the gap between the cathode plate and the support, seal each solder joint, and seal the wire part connected to the cathode plate in epoxy resin.

[0106] S8: Let stand for 24 hours to allow the epoxy resin to cure;

[0107] S9: Tear off the aluminum foil tape at the bottom of the cathode plate, and polish the cathode surface with sandpaper to obtain the cathode plate.

[0108] It should be noted that in this embodiment of the invention, each cathode plate in the cathode plate is welded with a wire in order to determine the current distribution in different parts of the cathode.

[0109] Specifically, following the previous example, based on Figures 2 to 4The electrolytic cell system shown employs a cathode plate with welded wires prepared as described above. Taking an alkaline electrolytic cell for hydrogen production as an example, the reaction products include hydrogen and oxygen, and the electrolyte is a KOH aqueous solution. The current density distribution is analyzed using experimental methods and the multiphysics simulation modeling method for electrolytic cells provided by this invention. Specifically, based on the above electrolytic cell system, 92 wires of the cathode plate are connected to a circuit board, and then one wire is output to the negative terminal of a DC power supply. The terminals of the anode plate are connected to the positive terminal of the DC power supply via electrode clamps. Then, a current recorder records the cathode current values ​​output from 92 channels. Specifically, the 92 wires of the cathode plate of the electrolytic cell system are connected to the circuit board, which is connected to the current recorder and the negative terminal of the DC power supply respectively; the anode plate of the electrolytic cell system is connected to the positive terminal of the DC power supply, and then the electrolyte in the water bath is introduced into the inlet of the electrolytic cell system through a diaphragm pump, and then flows out from the outlet back into the water bath. After connecting all the above devices, first turn on the current recorder to put it into operation; then turn on the diaphragm pump power supply and feed the electrolyte into the electrolytic cell using a bottom-in, top-out method. When liquid continuously flows into the outlet pipe, it indicates that the electrolytic cell is full of electrolyte. At this time, turn on the DC power input voltage. When bubbles are continuously generated on the cathode surface, it indicates that electrolysis is proceeding normally. By changing the operating conditions according to the experimental plan, the changes in current value can be detected in real time on the current recorder display, thus obtaining experimental data. Simultaneously, the operation process of the electrolytic cell system is simulated using a multiphysics simulation modeling method to obtain simulation data.

[0110] Figure 5 A comparison graph of experimental and simulated data is shown. Figure 6 The current density in the xz plane varies with the z-axis; Figure 7 A contour plot of simulated local current density data for the cathode plate is shown. Figure 8 A contour plot of experimental data on the local current density of the cathode plate is shown. Figure 5 It can be seen that the average relative error between the simulated and experimental current density data is 0.5%, and the simulated temperature change curve matches the experimental measurement results very well. Through comparison... Figures 6 to 8 It can be seen that the electric field distribution of the simulated data and the experimental data have a good agreement. Therefore, it is proven that the simulation modeling method of the present invention can accurately simulate the actual situation. It should be noted that... Figure 5 The horizontal axis represents temperature, and the vertical axis represents average current density. Figure 6 The horizontal axis is the z-axis, and the vertical axis is the current density.

[0111] In a more specific embodiment, following the previous example, the effects of changing the input voltage, electrolyte temperature, inlet flow rate, and inlet pipe angle on the performance of the cylindrical electrolyzer were analyzed using the multiphysics simulation modeling method of the present invention. The results showed that: 1) With increasing input voltage, the current density on the electrode surface significantly increases, accelerating the electrode reaction rate and altering the flow field and concentration balance inside the electrolyzer. This intensifies the influence of the flow field on the electric field distribution on the electrode surface, and the electric field uniformity gradually deteriorates; 2) Increased electrolyte temperature reduces the reversible potential and other overpotentials, with the simulated current density increasing by approximately 69.8%. While improving the performance of the electrolytic cell; however, the increase in temperature also leads to a decrease in the uniformity of current density; 3) The increase in inlet flow rate will lead to an increase in the current density on the electrode surface. Experiments have confirmed that the increase is about 2.47%, and the increased flow rate helps the bubbles to detach and the alkaline solution in the cathode chamber to metabolize faster, thus improving the performance of the electrolytic cell; 4) The angle of the inlet pipe at the inlet affects the internal flow field and the interaction of various physical fields in the electrolytic cell. When the inlet pipe is parallel to the direction of gravity, the increase in flow rate helps to increase the current density, and the standard deviation of the current density shows a trend of first increasing and then decreasing. At this time, the influence of the flow field on the electric field is weaker than when the inlet pipe is at 45° to gravity.

[0112] like Figure 9 , Figure 10 As shown, this embodiment of the invention provides a simulation modeling device for multiphysics fields in an electrolytic cell. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, as... Figure 9 The diagram shown is a hardware architecture diagram of a computing device housing a multiphysics simulation modeling device for an electrolytic cell provided in an embodiment of the present invention. (Except for...) Figure 9 In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 10 As shown, a device in a logical sense is formed by the CPU of its computing device reading the corresponding computer program from non-volatile memory into memory and running it. This embodiment provides a simulation modeling device for multiphysics fields in an electrolytic cell, which includes:

[0113] The acquisition module 1001 is used to acquire the geometric and physical parameters of the electrolytic cell;

[0114] Module 1002 is used to establish a three-dimensional geometric model of the electrolytic cell based on geometric parameters. Based on physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, it establishes an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational effect model of the electrolytic cell, and completes the simulation through coupling. Among them, the electrochemical model adopts a secondary current distribution; the two-phase flow model is used to simulate the electrolyte convection caused by bubbles and the turbulence caused by the electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model is used to simulate diffusion and convective transport; the temperature field model is used to simulate conductive heat transfer and convective heat transfer; and the gravitational effect model is used to simulate the flow of bubbles and electrolyte under the action of gravity.

[0115] In some specific implementations, the acquisition module 1001 can be used to perform the above step 100, and the construction module 1002 can be used to perform the above steps 102 and 104.

[0116] Specifically, the contents of the above-mentioned device are based on the same concept as the method embodiments of the present invention, and the specific contents can be found in the description of the method embodiments of the present invention, and will not be repeated here.

[0117] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a simulation modeling device for multiphysics in an electrolytic cell. In other embodiments of the present invention, a simulation modeling device for multiphysics in an electrolytic cell may include more or fewer components than illustrated, or combine some components, or split some components, or arrange different components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0118] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0119] This invention also provides a computing device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a simulation modeling method for multiphysics fields of an electrolytic cell according to any embodiment of this invention.

[0120] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program causes the processor to perform a simulation modeling method for multiphysics fields in an electrolytic cell according to any embodiment of this invention.

[0121] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform a simulation modeling method for multiphysics fields of an electrolytic cell as described in any of the above embodiments.

[0122] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0123] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0124] Examples of storage media used to provide program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0125] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0126] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0127] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0128] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation modeling method for multiphysics fields in an electrolytic cell, characterized in that, include: Obtain the geometric and physical parameters of the electrolytic cell; A three-dimensional geometric model of the electrolytic cell is established based on the geometric parameters; Based on the physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational effect model of the electrolytic cell are established, and simulation is performed through coupling. The electrochemical model employs a secondary current distribution; the two-phase flow model simulates electrolyte convection caused by bubbles and turbulence caused by electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model simulates diffusion and convective transport; the temperature field model simulates conductive and convective heat transfer; and the gravitational effect model simulates the flow of bubbles and electrolyte under gravitational influence.

2. The method according to claim 1, characterized in that, The electrochemical model includes: Among them, E eq E is the equilibrium voltage; T is the temperature; E eq,ref (T) is the reference equilibrium voltage at temperature T; R is the universal gas constant; n is the number of participating electrons; F is the Faraday constant; P i For species pressure; v i i is the stoichiometric coefficient; loc,expr i is the local current density at the cathode or anode; i0 is the exchange current density; η is the overpotential; α a α is the anodic reaction transfer coefficient; c is the cathode reaction transfer coefficient.

3. The method according to claim 1, characterized in that, The two-phase flow model employs the mass conservation equation, momentum balance equation, turbulence equation, and bubble dispersion equation. The mass conservation equation includes: Among them, u c The velocity of the liquid phase in the electrolyzer; u d φ is the velocity of the gas phase inside the electrolytic cell. d φ is the gas phase volume fraction. c The volume fraction of the liquid phase; m dc ρ is the mass transfer rate from gas to liquid. c ρ d These are the densities of the liquid phase and the gas phase, respectively; D md μ is the turbulence dispersion coefficient. T σ is the turbulent viscosity; T For turbulent Schmidt number; The momentum balance equations include: Where p is the mixing pressure; I is the identity matrix; τ c τ d ρ represents the viscous stress tensor of the liquid phase and the gas phase, respectively; g is the acceleration due to gravity; F m,c F m,d These are the interphase momentum transfer phases, namely the liquid phase and the gas phase; F c F m,d These are other volume forces related to the liquid and gas phases, respectively; u int The phase velocity; The turbulence equations include: Among them, u m The mass-average mixing rate; μ is the viscosity; σ is the average mixing rate. k C ε,1 C ε,2 C μ These are the standard k-ε model constants; k is the turbulent kinetic energy; and ε is the kinetic energy dissipation rate. The bubble dispersion equation includes: in, For the volumetric force of bubble dispersion; K g d is the gas phase dispersion coefficient; b U is the diameter of the bubble; r This represents the slip velocity.

4. The method according to claim 1, characterized in that, The concentration field model includes: Among them, J i U is the mass diffusion flux; u is the average mass velocity; C i R represents species concentration. i For species reaction rate; The concentration field model also includes setting flux boundary conditions by coupling the electrode surface: Where m represents the reaction at the electrode-electrolyte interface; v i i is the stoichiometric coefficient; loc This represents the local current density.

5. The method according to claim 1, characterized in that, The temperature field model includes: Among them, C p Q is the constant-pressure molar heat capacity of the electrolytic cell; K is the thermal conductivity; Q h Q is the total heat source; JH The pyrogen term for the Joule heating of the electrodes and electrolytes; Q m It is a local heat source generated by an electrochemical reaction process; φ s The potential of the electrode phase; φ l The potential of the electrolyte phase; i s i represents the current density of the electrode phase; l Q represents the current density in the electrolyte phase. b,tot The total heat source generated by the electrochemical reaction on the electrode surface; a v,m Specific surface area.

6. The method according to any one of claims 1 to 5, characterized in that, In the electrochemical model, electrode kinetic parameters, electrolyte conductivity, effective electrolyte conductivity in the membrane, and effective electrolyte conductivity in the electrolyte chamber are used as electrode reaction boundaries. The two-phase flow model uses gas phase mass flow rate and liquid phase mass flow rate as the flow field boundary conditions.

7. A simulation modeling device for multiphysics fields in an electrolytic cell, characterized in that, include: The acquisition module is used to acquire the geometric and physical parameters of the electrolytic cell; A construction module is used to establish a three-dimensional geometric model of the electrolytic cell based on the geometric parameters; Based on the physical parameters and the electrolyte, electrochemical reaction, and reaction products within the electrolytic cell, an electrochemical model, a two-phase flow model, a concentration field model, a temperature field model, and a gravitational effect model of the electrolytic cell are established, and simulation is performed through coupling. The electrochemical model employs a secondary current distribution; the two-phase flow model simulates electrolyte convection caused by bubbles and turbulence caused by electrolyte entering the electrolytic cell through the inlet pipe; the concentration field model simulates diffusion and convective transport; the temperature field model simulates conductive and convective heat transfer; and the gravitational effect model simulates the flow of bubbles and electrolyte under gravitational influence.

8. An electrolytic cell system, characterized in that, The method for implementing the method as described in any one of claims 1 to 6 includes: a cathode plate, an anode plate, and a diaphragm located at both ends of an electrolytic cell, and an electrolyte located within the electrolytic cell; both the cathode plate and the anode plate are circular; and the cathode plate is composed of a plurality of independent cathode sheets.

9. The electrolytic cell system according to claim 8, characterized in that, The cathode plate consists of 92 mutually insulated cathode sheets; and / or, The electrolytic cell includes a cathode side end plate, a cathode plate, a gasket, an electrolyte flow channel, a gasket, a diaphragm clamp, a diaphragm, a diaphragm clamp, a gasket, an electrolyte flow channel, a gasket, an anode plate, and an anode side end plate connected in sequence; wherein, the electrolyte flow channel is provided with an electrolyte inlet and an electrolyte outlet.

10. An application of a simulation modeling method for multiphysics fields in an electrolytic cell as described in any one of claims 1 to 6, characterized in that, Used to analyze the working characteristics of the electrolytic cell under target operating conditions or to monitor the current value passing through the cathode plate.

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