Finite element method-based pure uranium thin layer liquid film corrosion one-dimensional model method and device

Abstract

The invention discloses a finite element method-based pure uranium thin layer liquid film corrosion one-dimensional model method and device, and the method comprises the steps: constructing a one-dimensional model according to the relative humidity of a target environment and the liquid film thickness under the relative humidity; presetting basic parameters of the one-dimensional model; according to the basic parameters, establishing a reaction process of a gas-liquid interface, a liquid phase, a liquid-solid interface and uranium oxide precipitation in the one-dimensional model; carrying out current distribution initialization on a reaction process of a liquid phase and a liquid-solid interface to obtain an initial current potential distribution condition; taking the initial current potential distribution condition as an initial value, and performing transient solution on each reaction process to obtain a target current potential distribution condition; and according to the parameter value list of the liquid film thickness and the target current potential distribution condition, obtaining a corrosion result of each reaction process. The method can improve the simulation precision and efficiency of the corrosion one-dimensional model, and can be widely applied to the technical field of computer simulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of computer simulation, and in particular to a method and device for a one-dimensional model of thin-layer liquid film corrosion of pure uranium based on a finite element method. BACKGROUND

[0002] Due to its unique 5f orbital electron structure and extremely high chemical activity, uranium exhibits complex and variable multivalent corrosion behavior in the atmospheric environment. Traditional experimental methods are difficult to deeply analyze the transient reaction mechanism due to the radioactivity and toxicity of uranium. Although existing atmospheric corrosion models have achieved certain results in the thin liquid film corrosion mechanism of conventional metals, there is still a lack of accurate numerical simulation tools for the complex corrosion kinetics of uranium and other actinides. Existing corrosion models are roughly divided into two categories: analytical models and numerical models. Analytical models are difficult to handle complex boundary conditions and multi-field coupling problems, while numerical models use discrete methods such as finite elements and finite volumes, which have high computational costs and rely on a large number of accurate parameters. SUMMARY

[0003] Therefore, the embodiments of the present application mainly aim to provide a method and device for a one-dimensional model of thin-layer liquid film corrosion of pure uranium based on a finite element method, in order to solve at least one of the problems in the prior art, and improve the simulation accuracy and efficiency of the one-dimensional corrosion model.

[0004] To achieve the above-mentioned purpose, one aspect of the embodiments of the present application provides a method for a one-dimensional model of thin-layer liquid film corrosion of pure uranium based on a finite element method, which comprises:

[0005] constructing a one-dimensional model according to the relative humidity of the target environment and the liquid film thickness under the relative humidity;

[0006] pre-setting the basic parameters of the one-dimensional model;

[0007] establishing a first reaction process of the gas-liquid interface, a second reaction process of the liquid phase, a third reaction process of the liquid-solid interface, and a fourth reaction process of uranium oxide precipitation in the one-dimensional model according to the basic parameters;

[0008] initializing the current distribution of the second reaction process and the third reaction process to obtain an initial current potential distribution;

[0009] taking the initial current potential distribution as an initial value to perform transient solution on the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process, and obtain a target current potential distribution;

[0010] According to the parameter value list of the liquid film thickness and the target current potential distribution, corrosion results of the first reaction process, the second reaction process, the third reaction process and the fourth reaction process are obtained.

[0011] In some embodiments, the method further comprises the following steps:

[0012] The corrosion results are one-dimensionally parameterized and stretched to generate a two-dimensional corrosion result map.

[0013] In some embodiments, the constructing a one-dimensional model according to the relative humidity of the target environment and the liquid film thickness under the relative humidity comprises the following steps:

[0014] The liquid phase is taken as a middle line of the one-dimensional model;

[0015] The gas-liquid interface is taken as a top end of the one-dimensional model;

[0016] The liquid-solid interface is taken as a bottom end of the one-dimensional model;

[0017] The length of the one-dimensional model is preset according to the relative humidity of the target environment.

[0018] In some embodiments, the basic parameters include liquid film thickness, oxygen flux at the gas-liquid interface, oxygen solubility in the liquid phase, initial oxygen concentration, oxygen concentration at the gas-liquid interface, diffusion constant, reaction rate constant, density and molar mass of uranium and uranium oxide.

[0019] In some embodiments, the establishing the first reaction process of the gas-liquid interface in the one-dimensional model comprises the following steps:

[0020] The first reaction process of oxygen dissolving from the atmospheric environment to the liquid phase at the gas-liquid interface is established.

[0021] In some embodiments, the establishing the second reaction process of the liquid phase in the one-dimensional model comprises the following steps:

[0022] The diffusion process of uranium ions, uranium oxide and oxygen in the liquid phase is established;

[0023] The electric field migration process of uranium ions, uranium oxide and oxygen in the liquid phase is established;

[0024] The chemical reaction of uranium ions, uranium oxide and oxygen in the liquid phase is established;

[0025] The precipitation process of uranium ions in the liquid phase is established.

[0026] In some embodiments, the establishing the third reaction process of the liquid-solid interface in the one-dimensional model comprises the following steps:

[0027] establishing an electrochemical reaction process of the uranium in the liquid-solid interface;

[0028] establishing a precipitation process of the uranium oxide in the liquid-solid interface.

[0029] In some embodiments, a fourth reaction process of the uranium oxide precipitation in the one-dimensional model is established, including the steps of:

[0030] establishing a process of the precipitate as an oxidation film to inhibit corrosion of the uranium surface.

[0031] To achieve the above object, another aspect of the embodiment of the present application provides a device of a one-dimensional model of liquid film corrosion of a pure uranium thin layer based on a finite element method, the device comprising:

[0032] a model construction module, configured to construct a one-dimensional model according to a relative humidity of a target environment and a liquid film thickness under the relative humidity;

[0033] a parameter acquisition module, configured to pre-set basic parameters of the one-dimensional model;

[0034] a reaction process construction module, configured to establish, according to the basic parameters, a first reaction process of a gas-liquid interface, a second reaction process of a liquid phase, a third reaction process of a liquid-solid interface and a fourth reaction process of uranium oxide precipitation in the one-dimensional model;

[0035] a first current potential distribution acquisition module, configured to initialize a current distribution of the second reaction process and the third reaction process to obtain an initial current potential distribution;

[0036] a second current potential distribution acquisition module, configured to take the initial current potential distribution as an initial value, and perform transient solution on the first reaction process, the second reaction process, the third reaction process and the fourth reaction process to obtain a target current potential distribution;

[0037] a corrosion result acquisition module, configured to obtain a corrosion result of the first reaction process, the second reaction process, the third reaction process and the fourth reaction process according to a parameter value list of the liquid film thickness and the target current potential distribution.

[0038] To achieve the above object, another aspect of the embodiment of the present application provides an electronic device, which comprises a memory and a processor, the memory stores a computer program, and the processor implements the method described above when executing the computer program.

[0039] To achieve the above object, another aspect of the embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the method described above.

[0040] To achieve the above object, another aspect of the embodiment of the present application provides a computer program product or computer program, which comprises computer instructions stored in a computer readable storage medium. The processor of a computer device can read the computer instructions from the computer readable storage medium, and the processor executes the computer instructions to make the computer device execute the method described above.

[0041] The embodiment of the present application has at least the following beneficial effects: the present application provides a method and device for a one-dimensional model of liquid film corrosion of a pure uranium thin layer based on a finite element method, the scheme constructs a one-dimensional model according to the relative humidity of a target environment and the liquid film thickness under the relative humidity, breaks through the safety limit of experimental research caused by the high radioactivity and toxicity of uranium through a digital corrosion model, pre-sets basic parameters of the one-dimensional model, establishes a first reaction process of a gas-liquid interface, a second reaction process of a liquid phase, a third reaction process of a liquid-solid interface and a fourth reaction process of uranium oxide precipitation in the one-dimensional model according to the basic parameters, simulates the reaction process through the one-dimensional model, reduces the data volume, improves the corrosion model simulation efficiency on the premise of ensuring the simulation accuracy, initializes the current distribution for the second reaction process and the third reaction process to obtain an initial current potential distribution, takes the initial current potential distribution as an initial value to perform transient solution for the first reaction process, the second reaction process, the third reaction process and the fourth reaction process to obtain a target current potential distribution, and obtains the corrosion results of the first reaction process, the second reaction process, the third reaction process and the fourth reaction process according to a parameter value list of the liquid film thickness and the target current potential distribution, thereby providing key theoretical support and technical foresight for long-term storage, safe application and corrosion protection of uranium materials. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0043] Figure 1 is a flow chart of the method for a one-dimensional model of liquid film corrosion of a pure uranium thin layer based on a finite element method provided by the embodiment of the present application;

[0044] Figure 2This is a schematic diagram of a one-dimensional model of thin liquid film corrosion in atmospheric corrosion provided in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the uranium-related reactions occurring at the gas-liquid and liquid-solid interfaces at both ends and the liquid phase in the middle in a one-dimensional model provided in the embodiments of the present invention, as well as the states of the substances involved in these reactions.

[0046] Figure 4 This is a schematic diagram of mesh division in a one-dimensional model provided in an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram showing the thickness change of a uranium metal surface under a 1mm liquid film within 600s, as provided in an embodiment of the present invention, and the thickness changes of each of the dissolution and precipitation reaction formulas.

[0048] Figure 6 This is a schematic diagram showing the thickness change of a uranium metal surface under a 1mm liquid film within 600s, as provided in an embodiment of the present invention, and the mass change of each of the dissolution and precipitation reaction formulas.

[0049] Figure 7 This is a schematic diagram of one-dimensional parametric stretching provided in an embodiment of the present invention;

[0050] Figure 8 Within 600 seconds as provided in the embodiments of the present invention, U 3+ U 4+ A schematic diagram showing the concentration of O2 and the distribution of pH in a 1 mm thick liquid film;

[0051] Figure 9 Within 600 seconds as provided in the embodiments of the present invention, U 3+ Schematic diagram of distribution in liquid films of different thicknesses;

[0052] Figure 10 This is a schematic diagram showing the distribution of O2 in liquid films of different thicknesses within 600 seconds, provided by an embodiment of the present invention.

[0053] Figure 11 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the invention 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 merely illustrative of the invention and are not intended to limit the invention. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this invention; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this invention as detailed in the appended claims.

[0055] It should be noted that although functional modules are divided in the system diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first / S100" and "second / S200" in the specification, claims, and the foregoing drawings may be used herein to describe various concepts, but unless specifically stated otherwise, these concepts are not limited by these terms. These terms are used only to distinguish one concept from another. For example, first information may also be referred to as second information without departing from the scope of the embodiments of the invention, and similarly, second information may also be referred to as first information. Depending on the context, the words "if" or "when" as used herein may be interpreted as "when," "in response to a determination," or "in the event of a determination."

[0056] The terms “at least one,” “multiple,” “each,” “any,” etc., used in this invention, “at least one” includes one, two, or more than two; “multiple” includes two or more than two; “each” refers to each of the corresponding multiple; and “any” refers to any one of the multiple.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0058] Uranium exhibits chemical reactivity and complex reaction mechanisms far exceeding those of conventional metals due to the unique arrangement of its 5f orbital electrons. Unlike the corrosive behavior of traditional metals such as iron and aluminum, uranium's 5f orbital electron cloud has a complex spatial distribution, weak shielding effect, and energy levels close to the valence electron shell, making it highly susceptible to multivalent oxidation reactions with environmental media such as oxygen, water vapor, and hydrogen, generating corrosion products such as uranium oxides and hydrides. Therefore, uranium not only possesses extremely high chemical reactivity but also exhibits significant characteristics such as the coexistence of multiple valence states, intertwined reaction pathways, and complex product phase transitions. Furthermore, uranium's high radioactivity, extreme toxicity, and extreme environmental sensitivity pose severe challenges to experimental research. The high radioactivity and toxicity of uranium impose stringent safety restrictions on experimental research, making it difficult for conventional characterization techniques to capture transient reaction processes.

[0059] Metal corrosion can be classified into various types based on the environmental medium, including atmospheric corrosion, seawater corrosion, and soil corrosion. Among these, atmospheric corrosion is the most severe due to its prevalence and insidious nature. Statistics show that economic losses caused by atmospheric corrosion account for approximately half of the total cost of all types of corrosion. Unlike uniform corrosion immersed in an electrolyte, atmospheric corrosion occurs in an environment of an extremely thin liquid film or microdroplets on the metal surface. This unique interfacial environment leads to a series of unique corrosion mechanisms. The thin liquid film effect causes atmospheric corrosion to exhibit electrochemical behavior that is drastically different from bulk solution corrosion. When the thickness of the liquid film on the metal surface decreases from the millimeter level to the micrometer level, the oxygen diffusion path shortens, and the cathodic reaction rate can increase by 2-3 orders of magnitude. At the same time, the local accumulation of corrosion products in the thin liquid film creates a unique microenvironment, and the pH value may deviate from the bulk solution by several units, further accelerating localized corrosion. Existing atmospheric corrosion models are mostly for conventional metals such as iron and copper, predicting corrosion behavior by analyzing electrochemical reactions under microdroplets or thin liquid films. However, atmospheric corrosion models for uranium are relatively rare.

[0060] With advancements in computational technology and theoretical research, corrosion prediction models have become an important tool to compensate for the limitations of experimental studies. Current corrosion models can be broadly categorized into analytical models and numerical models. Analytical models, based on simplified physicochemical equations (such as estimating corrosion rates by deriving the cathodic limiting current equation), offer advantages such as low computational cost and few parameter requirements, but struggle to handle complex boundary conditions and multi-field coupling problems. Numerical models, employing discretization methods like the finite element method and finite volume method, solve corrosion-related partial differential equations, considering more detailed factors, but incurring higher computational costs and relying on a large number of accurate parameters. Furthermore, the construction of thin-film corrosion models faces the challenge of the curse of dimensionality. If a complete three-dimensional model is used to simulate the reaction process in a thin-film liquid film, the increase in film size leads to an exponential increase in the number of meshes, resulting in a dramatic expansion of computational data. This not only significantly prolongs computation time but may also lead to difficulties in solving the problem or even failure to converge due to mesh distortion, numerical instability, and other issues.

[0061] In view of this, such as Figure 1 As shown, this embodiment of the invention provides a method for a one-dimensional model of pure uranium thin-film corrosion based on the finite element method. This method may include, but is not limited to, steps S100 to S600:

[0062] Step S100: Construct a one-dimensional model based on the relative humidity of the target environment and the thickness of the liquid film at the relative humidity.

[0063] Step S200: Preset the basic parameters of the one-dimensional model;

[0064] Step S300: Based on the basic parameters, establish the first reaction process of the gas-liquid interface, the second reaction process of the liquid phase, the third reaction process of the liquid-solid interface, and the fourth reaction process of uranium oxide precipitation in the one-dimensional model.

[0065] Step S400: Initialize the current distribution for the second and third reaction processes to obtain the initial current potential distribution.

[0066] Step S500: Using the initial current potential distribution as the initial value, perform transient solutions on the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process to obtain the target current potential distribution.

[0067] Step S600: Based on the list of parameters for liquid film thickness and the target current potential distribution, the corrosion results of the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process are obtained.

[0068] In step S100 of some embodiments, the length of the one-dimensional model is set according to the thickness of the thin liquid film under the target ambient humidity, and one end of the one-dimensional model is set as the gas-liquid interface, the other end as the liquid-solid interface, and the line in the middle is the liquid phase. Here, liquid phase is distinguished by phase, while liquid film is the actual term. In fact, both liquid phase and liquid film refer to the liquid film formed by atmospheric condensation on the metal surface in the one-dimensional model.

[0069] In some embodiments, step S100 may include, but is not limited to, steps S110 to S140:

[0070] Step S110: Use the liquid phase as the middle line of the one-dimensional model;

[0071] Step S120: Use the gas-liquid interface as the top of the one-dimensional model;

[0072] Step S130: Use the liquid-solid interface as the bottom of the one-dimensional model;

[0073] Step S140: Preset the length of the one-dimensional model based on the relative humidity of the target environment.

[0074] In some embodiments, steps S110 to S140, such as Figure 2As shown, the mechanism of atmospheric corrosion involves the condensation of a thin water layer on the metal surface by moist air. The thin liquid film electrolyte acts as the ionic electrode, and the uranium metal acts as the electronic electrode, together forming an electrochemical corrosion cell. The thin liquid film of atmospheric corrosion ranges from a few molecular layers to millimeters in thickness, a relatively small scale compared to the metal surface. In the longitudinal direction of the thin liquid film, the surrounding scale varies greatly, thus it can be considered infinitely far within a certain range, or in other words, the distribution of matter, chemical and electrochemical reactions are uniform within this range. Therefore, in atmospheric corrosion, the distribution and diffusion of matter, as well as chemical and electrochemical reactions, in the longitudinal direction of the liquid film can be represented by a one-dimensional line segment. For example, a one-dimensional model is constructed. The top of the one-dimensional model represents the gas-liquid interface, i.e., the surface where the liquid film contacts the atmospheric phase, where the dissolution of oxygen from the atmosphere mainly occurs; the bottom of the one-dimensional model represents the liquid-solid interface, i.e., the surface where the liquid film contacts the uranium metal phase, where electrochemical reactions and precipitation accumulation mainly occur; the lines in the middle of the one-dimensional model represent the liquid phase, i.e., the thin liquid film with water as the electrolyte, where matter diffusion and chemical reactions mainly occur. Furthermore, the length of the one-dimensional model can be customized based on the relative humidity of the target environment in which the uranium material is used. Optionally, the liquid film thickness in the one-dimensional model can be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, and 1 mm.

[0075] In step S200 of some embodiments, basic parameters of the one-dimensional model are preset, including initial concentration, diffusion constant, reaction rate, reference potential current, transfer coefficient, etc., as well as properties of uranium, uranium ions, uranium oxide, oxygen, and the liquid film. Optionally, the basic parameters include liquid film thickness; oxygen flux limit at the gas-liquid interface; oxygen solubility in the liquid film; initial oxygen concentration; oxygen concentration at the gas-liquid interface; U 3+ U 4+ UO2, O2, H + OH - The diffusion constant, standard equilibrium potential related to electrochemical reactions, reference exchange current density and anodic transfer coefficient; the reaction rate constant of precipitation reactions; the equilibrium constant of dissolution of precipitates; the density and molar mass of uranium and uranium oxides; the total amount of moles available per unit surface area of ​​dissolved metals, etc.

[0076] In step S300 of some embodiments, based on basic parameters, relevant uranium reactions occurring at the gas-liquid ends, the liquid-solid interface, and the intermediate liquid phase in a one-dimensional model are established, along with the states of the substances involved in these reactions, such as... Figure 3 As shown.

[0077] In some embodiments, the first reaction process of the gas-liquid interface in a one-dimensional model is obtained by establishing the reaction process of oxygen dissolving from the atmospheric environment into the liquid film at the gas-liquid interface. Exemplarily, at the gas-liquid interface, the process of oxygen exchange between the gas and liquid occurs:

[0078]

[0079] In the formula, This represents the flux of oxygen at the gas-liquid interface; This refers to the concentration of dissolved oxygen at the surface of the liquid phase, which is close to the gas phase. The solubility of oxygen in this liquid film; denoted as the oxygen flux limit at the gas-liquid interface; n is the normal vector, perpendicular to the gas-liquid interface.

[0080] The reaction formulas involved are as follows:

[0081] O2(g)→O2(aq)

[0082] In some embodiments, establishing a second reaction process in the liquid phase of a one-dimensional model includes: establishing a diffusion process of uranium ions, uranium oxides, and oxygen in the liquid phase; establishing an electric field migration process of uranium ions, uranium oxides, and oxygen in the liquid phase; and establishing a chemical reaction of uranium ions, uranium oxides, and oxygen in the liquid phase. Additionally, it is necessary to separately establish the process of uranium ions undergoing a precipitation reaction, causing uranium oxide solids to precipitate onto the liquid-solid phase surface, i.e., establishing the precipitation process of uranium ions in the liquid phase. Exemplarily, for the liquid phase, there are the following material diffusion, chemical reaction, and precipitation reaction:

[0083] First, in a liquid environment, matter and charge are conserved:

[0084]

[0085] Among them, R i Let i be the amount of substance i; Let be the diffusion rate of substance i; c is the mass transfer rate. i Let be the concentration of substance i.

[0086] Then, the substance diffuses within the liquid film:

[0087]

[0088] Among them, D i Z is the diffusion constant; i represents all substances involved in the one-dimensional model; z i For charge; u m,i is the mobility; F is the Faraday constant; For gradient operator; φ l R is the potential in the liquid phase; R is the ideal gas constant; T is the temperature.

[0089] Then, chemical and precipitation reactions occur in the liquid phase:

[0090] H + (aq)+OH -(aq)→H2O(l)

[0091] U 4+ (aq) + 2H₂O(l) → UO₂(s) + 4H + (aq)

[0092] Regarding the self-ionization of water:

[0093] pK w =14.94-0.04209(T-273.15)+0.0001718(T-273.15) 2

[0094]

[0095] Among them, K w It is the ion product constant of water; pK w It is K w The negative logarithm; M is the concentration unit, mol / m³. 3 .

[0096] Regarding the precipitation reaction of uranium:

[0097]

[0098] in, It is the reaction formation rate of uranium oxide dissolved in the liquid phase; It is the reaction rate constant for the formation of uranium oxide; It's U 4+ The concentration; It is OH - The concentration; It is the solubility product constant of uranium oxide; the max operator takes the maximum value within the parentheses.

[0099] In addition, within the liquid film, along with the formation of uranium oxides, other substances also disappear and are generated:

[0100]

[0101] in, It's U 4+ Reaction formation rate; It is H + The reaction formation rate.

[0102] In some embodiments, establishing a third reaction process at the liquid-solid interface in a one-dimensional model includes: establishing an electrochemical reaction process involving uranium at the liquid-solid interface, including anodic dissolution of uranium and cathodic reduction of oxygen. Additionally, it is necessary to separately establish the uranium oxide precipitation process resulting from the electrochemical reaction and the uranium oxide precipitation process from the liquid film to the liquid-solid interface. Exemplarily, at the liquid-solid interface, the following electrochemical reaction occurs:

[0103] U(s) → U 3+ (aq)+3e -

[0104] U 3+ (aq)→ 4+ (aq)+e -

[0105] U(s) + 2H₂O(l) → UO₂(s) + 4H + (aq)+4e -

[0106] O2(aq) + H2O(l) + 4e - →4OH - (aq)

[0107] These electrochemical equations are governed by the Nernst equation and the BV equation for mass action:

[0108]

[0109] α c =n-α a

[0110] η=φ s -φ l -E eq

[0111] Among them, E eq E is the equilibrium potential. eq,ref (T) is the reference equilibrium potential; n is the charge of substance i; substance i is the substance involved in the above reaction; c i c is the concentration of substance i; i,ref v is the reference concentration of substance i; i Let i be the stoichiometric coefficient of substance i; i loc i is the local exchange current density; i0 is the equilibrium exchange current density; α a η is the anode transfer coefficient; η is the overpotential; α c i is the cathode transfer coefficient; 0,ref (T) represents the reference equilibrium exchange current density; φ s φ represents the initial potential of the solid phase. l This represents the liquid phase potential.

[0112] For dissolution and precipitation processes involved in electrochemical reactions:

[0113]

[0114] Where, R U v is the amount of substance U dissolved in v. U The stoichiometric coefficient of the dissolved substance U; This represents the amount of substance UO2 precipitated in the electrochemical reaction. The stoichiometric coefficient of the precipitate UO2 is given.

[0115] In some embodiments, for uranium oxide precipitation, the process of inhibiting uranium surface corrosion is achieved by establishing these uranium oxide precipitates as an oxide film, resulting in a fourth reaction process. Exemplarily, the process of corrosion product deposition at the liquid-solid interface needs to be discussed: for chemical reaction precipitation occurring in the liquid phase:

[0116]

[0117] in, is the formation rate of all precipitated substances UO2 in the liquid film; x is the thickness of the liquid film.

[0118] For electrochemical reactions and precipitation occurring at the liquid-solid interface:

[0119]

[0120] Therefore, at the solid-liquid interface:

[0121]

[0122]

[0123] in, The concentration of UO2 that precipitates to the solid-liquid interface and becomes a solid; t is time; Δt represents the concentration of UO2 that precipitates to the solid-liquid interface and becomes a solid at t=0; Δs represents the change in electrode surface thickness. The density of UO2; The molar mass of UO2; The rate at which UO2 precipitates to the solid-liquid interface and becomes a solid.

[0124] Alternatively, a similar equation can be used for the dissolution process:

[0125]

[0126] Among them, c s,U c is the concentration of dissolved U; s,U,0 ρ is the concentration of dissolved U at t=0.U The density of U; M U U is the molar mass; v d,U The rate at which U dissolves.

[0127] Furthermore, the deposition of corrosion products also inhibits the corrosion process.

[0128]

[0129] i 0,ref (T)=i 0,ref,i,a (T)*(1-θ)

[0130] Where θ is the coverage rate; It is the total molar concentration of UO2 on the electrode surface; It is the total amount of uranium metal dissolved per unit surface area available in moles; i 0,ref,a (T) is the reference exchange current density related to the anodic process.

[0131] In some embodiments, the one-dimensional model is meshed, uniformly dividing the one-dimensional model into extremely fine meshes. Optionally, as... Figure 4 As shown, using standard physics calibration and predefined extremely fine sizes, the one-dimensional model is divided into 100 equal parts. For a liquid film model with a thickness of 1 mm, the maximum element size is 0.01 mm, the maximum element growth rate is 1.1, and the growth rate in narrow regions is 1.

[0132] In steps S400 to S500 of some embodiments, the initial current potential distribution of the second reaction process in the liquid phase and the third reaction process at the liquid-solid interface is first initialized using the current distribution. Then, using the initial current potential distribution as the initial value, transient calculations are performed on the reaction processes of the liquid phase, liquid-solid interface, gas-liquid interface, and uranium oxide precipitation at different times to obtain the target current potential distribution. Optionally, in the one-dimensional model, the transient calculation time unit is seconds, the initial value is 0, the step size is 1, the end value is 600, and the tolerance is controlled by the physical field.

[0133] In step S600 of some embodiments, only the parameter value of the liquid film thickness is changed, without altering the overall framework of the one-dimensional model, for simple batch calculations. A preset list of liquid film thickness parameter values ​​is used. Through parametric scanning, based on the target current potential distribution, these different liquid film thickness values ​​are used sequentially for calculations, while retaining all solutions, thereby obtaining the corrosion results of the one-dimensional model corresponding to each liquid film thickness. Optionally, the parameter value list is {0.1, 0.3, 0.5, 0.7, 1}, in mm.

[0134] In some embodiments, the method for a one-dimensional model of pure uranium thin-film liquid film corrosion based on the finite element method further includes: performing one-dimensional parametric stretching on the corrosion results to generate a two-dimensional corrosion result map. Since the calculation of the one-dimensional model involves time and spatial distribution, plotting the results using a one-dimensional line graph would be very cumbersome and complex. Therefore, a contour plot is used, where the horizontal axis represents time, the vertical axis represents the liquid film height, and the contour lines represent a two-dimensional concentration graph. This requires processing the model results. One-dimensional parametric stretching is used, such as... Figure 7 As shown, one-dimensional parametric stretching stitches together the one-dimensional line segments at each time point into a two-dimensional graph as a time series. The data source uses all solutions from the one-dimensional model, with no level variation and a level scaling factor of 1.

[0135] In some embodiments, some results calculated using the one-dimensional model are as follows:

[0136] refer to Figure 5 This demonstrates the total thickness variation of the uranium surface at a 1 mm liquid film thickness, as well as the thickness variations caused by dissolution or precipitation resulting from chemical and electrochemical reactions. (Reference) Figure 6 This study demonstrates the total mass change of a uranium sheet with a diameter of 10 mm and a thickness of 3 mm over 600 seconds in this atmosphere, as well as the mass changes caused by dissolution or precipitation resulting from chemical and electrochemical reactions. This illustrates that the one-dimensional model of this invention can deeply explore the reaction equations involved in changes in the state of matter and accurately compare and analyze the main influencing factors—a level of precision that is difficult to achieve with traditional experimental methods.

[0137] refer to Figure 8 This demonstrates the concentration of substances at different heights within a 1 mm thick liquid film over 600 seconds. It allows for the analysis of changes in different substances at different times and liquid film heights, as well as the analysis of… Figure 8 The example illustrates the relationships between four substances to understand the effect of substance concentration on reaction and diffusion at certain times.

[0138] like Figure 9 and Figure 10 As shown, the concentrations of uranium ions and oxygen at different heights within the liquid film over 10 minutes are illustrated with varying liquid film thicknesses. It can be observed that different liquid film thicknesses affect the concentration of substances within the liquid film; as the liquid film thins, oxygen transport becomes faster, the ion concentration inside the liquid film increases, and the reaction and diffusion processes exhibit different characteristics.

[0139] This invention also provides an apparatus for a one-dimensional model of pure uranium thin-film liquid film corrosion based on the finite element method, which can implement the above-described method. The apparatus includes:

[0140] The model construction module is used to construct a one-dimensional model based on the relative humidity of the target environment and the thickness of the liquid film at that relative humidity.

[0141] The parameter acquisition module is used to preset the basic parameters of a one-dimensional model.

[0142] The reaction process construction module is used to establish the first reaction process of the gas-liquid interface, the second reaction process of the liquid phase, the third reaction process of the liquid-solid interface, and the fourth reaction process of uranium oxide precipitation in a one-dimensional model based on basic parameters.

[0143] The first current potential distribution acquisition module is used to initialize the current distribution of the second and third reaction processes and obtain the initial current potential distribution.

[0144] The second current potential distribution acquisition module is used to take the initial current potential distribution as the initial value and perform transient solutions on the first reaction process, the second reaction process, the third reaction process and the fourth reaction process to obtain the target current potential distribution.

[0145] The corrosion result acquisition module is used to obtain the corrosion results of the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process based on the list of parameter values ​​of liquid film thickness and the target current potential distribution.

[0146] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0147] This invention also provides an electronic device, which includes a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including a tablet computer, an in-vehicle computer, or similar device.

[0148] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0149] refer to Figure 11 , Figure 11 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0150] The processor 701 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention.

[0151] The memory 702 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 702 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 702 and is called and executed by the processor 701.

[0152] The input / output interface 703 is used to implement information input and output;

[0153] The communication interface 704 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0154] Bus 705 transmits information between various components of the device (e.g., processor 701, memory 702, input / output interface 703, and communication interface 704);

[0155] The processor 701, memory 702, input / output interface 703, and communication interface 704 are connected to each other within the device via bus 705.

[0156] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0157] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0158] This invention also provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions to cause the computer device to perform the aforementioned method.

[0159] In summary, the method and apparatus for a one-dimensional model of pure uranium thin-film liquid film corrosion based on the finite element method according to embodiments of the present invention have the following advantages:

[0160] 1. Compared to other common metals, uranium exhibits complex corrosion reactions involving numerous substances, making direct experimental testing difficult due to its hazardous nature. Atmospheric corrosion primarily involves electrochemical corrosion under humid air and a thin liquid film. To study reactions and material changes within millimeter-thinner liquid films, finite element method (FEM) calculations offer significant advantages over actual experiments. Furthermore, uranium corrosion involves multiple substances and reactions; using a three-dimensional model would not only drastically increase the mesh size and data volume but also delay computation time and potentially render the solution unsolvable. Therefore, a reasonable one-dimensional model can mitigate the curse of dimensionality to a certain extent. This invention presents a uranium atmospheric corrosion model based on a low-dimensional finite element method, which not only overcomes the limitations of experimental research but also provides crucial theoretical support and technological insights for the long-term storage, safe application, and corrosion protection of uranium materials.

[0161] 2. The embodiments of the present invention simulate the reaction process using a one-dimensional model, thereby reducing the amount of data and improving the simulation efficiency of the corrosion model while ensuring simulation accuracy.

[0162] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is altered and sub-operations described as part of a larger operation are executed independently.

[0163] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the described functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0164] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0165] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0166] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0167] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0168] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0169] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0170] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A method for a one-dimensional model of pure uranium thin-film liquid film corrosion based on the finite element method, characterized in that, Includes the following steps: A one-dimensional model is constructed based on the relative humidity of the target environment and the thickness of the liquid film at that relative humidity. The basic parameters of the one-dimensional model are preset; Based on the aforementioned basic parameters, the first reaction process at the gas-liquid interface, the second reaction process in the liquid phase, the third reaction process at the liquid-solid interface, and the fourth reaction process for uranium oxide precipitation in the one-dimensional model are established. The current distribution of the second and third reaction processes is initialized to obtain the initial current potential distribution. Using the initial current potential distribution as the initial value, transient solutions are performed on the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process to obtain the target current potential distribution. Based on the list of parameters for the liquid film thickness and the distribution of the target current potential, the corrosion results of the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process are obtained.

2. The method according to claim 1, characterized in that, The method further includes the following steps: The corrosion results are subjected to one-dimensional parametric stretching to generate a two-dimensional corrosion result image.

3. The method according to claim 1, characterized in that, The process of constructing a one-dimensional model based on the relative humidity of the target environment and the liquid film thickness at that relative humidity includes the following steps: The liquid phase is used as the middle line of the one-dimensional model; The gas-liquid interface is used as the top of the one-dimensional model; The liquid-solid interface is used as the bottom of the one-dimensional model; The length of the one-dimensional model is preset based on the relative humidity of the target environment.

4. The method according to claim 1, characterized in that, The basic parameters include liquid film thickness, oxygen flux at the gas-liquid interface, oxygen solubility in the liquid phase, initial oxygen concentration, oxygen concentration at the gas-liquid interface, diffusion constant, reaction rate constant, and density and molar mass of uranium and uranium oxides.

5. The method according to claim 1, characterized in that, The first reaction process for establishing the gas-liquid interface in the one-dimensional model includes the following steps: Establish the first reaction process by which oxygen dissolves from the atmospheric environment into the liquid phase at the gas-liquid interface.

6. The method according to claim 1, characterized in that, Establishing the second reaction process in the liquid phase of the one-dimensional model includes the following steps: Establish the diffusion process of uranium ions, uranium oxides, and oxygen in the liquid phase; Establish the electric field migration process of uranium ions, uranium oxides, and oxygen in the liquid phase; Establish the chemical reaction between uranium ions, uranium oxides, and oxygen in the liquid phase; Establish the precipitation process of uranium ions in the liquid phase.

7. The method according to claim 1, characterized in that, Establishing the third reaction process at the liquid-solid interface in the one-dimensional model includes the following steps: Establish the electrochemical reaction process of uranium at the liquid-solid interface; Establish the precipitation process of uranium oxide at the liquid-solid interface.

8. The method according to claim 1, characterized in that, The fourth reaction process for uranium oxide precipitation in the one-dimensional model includes the following steps: The process of establishing a precipitate as an oxide film to inhibit uranium surface corrosion.

9. A device for a one-dimensional model of pure uranium thin-film liquid film corrosion based on the finite element method, characterized in that, include: The model construction module is used to construct a one-dimensional model based on the relative humidity of the target environment and the liquid film thickness at the relative humidity. The parameter acquisition module is used to preset the basic parameters of the one-dimensional model; The reaction process construction module is used to establish, based on the basic parameters, the first reaction process of the gas-liquid interface, the second reaction process of the liquid phase, the third reaction process of the liquid-solid interface, and the fourth reaction process of uranium oxide precipitation in the one-dimensional model. The first current potential distribution acquisition module is used to initialize the current distribution of the second reaction process and the third reaction process to obtain the initial current potential distribution. The second current potential distribution acquisition module is used to take the initial current potential distribution as the initial value and perform transient solutions on the first reaction process, the second reaction process, the third reaction process and the fourth reaction process to obtain the target current potential distribution. The corrosion result acquisition module is used to obtain the corrosion results of the first reaction process, the second reaction process, the third reaction process, and the fourth reaction process based on the list of parameter values ​​of the liquid film thickness and the target current potential distribution.

10. An electronic device, characterized in that, Including the processor and memory; The memory is used to store programs; The processor executes the program to implement the method as described in any one of claims 1 to 8.

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