Aluminum electrolysis cell furnace wall and current density calculation method and device, storage medium and product

Abstract

The invention discloses an aluminum electrolysis cell furnace wall and current density calculation method and device, a storage medium and a product, and the method comprises the steps: building an electric-magnetic coupling model of a conductive region according to the structure parameters and process parameters of an aluminum electrolysis cell, and calculating the electromagnetic force distribution of an electrolyte and a molten aluminum region based on the electric-magnetic coupling model; the method comprises the following steps: constructing an anode bubble-electrolyte-molten aluminum three-phase flow coupling model according to structure parameters and process parameters of an aluminum electrolysis cell, and calculating bubble driving force distribution of an electrolyte area and a molten aluminum area based on the anode bubble-electrolyte-molten aluminum three-phase flow coupling model; constructing an aluminum electrolysis cell three-dimensional model according to the structure parameters and the process parameters of the aluminum electrolysis cell; electromagnetic force distribution and bubble driving force distribution are used as momentum sources, a full-cell electricity-heat-flow strong coupling model is constructed, and aluminum electrolysis cell furnace wall and current density distribution is calculated. Strong coupling calculation and analysis among the electric field, the thermal field, the flow field and the furnace wall can be achieved, and the method is closer to industrial practice.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum electrolysis, and in particular relates to a furnace side and current density calculation method, equipment, storage medium and product of an aluminum electrolysis cell. Background Art

[0002] Aluminum electrolytic cell is a high-temperature molten salt electrolysis equipment used to produce metallic aluminum. During the startup and operation of aluminum electrolytic cell, the melt (including electrolyte and aluminum liquid) and the side lining are formed by electrolyte solidification. On the one hand, the furnace side protects the lining and prevents the lining from being eroded by high-temperature electrolyte and aluminum liquid; on the other hand, it plays a role of heat preservation, reducing the Joule heat in the melt from being lost from the side to the surrounding environment, ensuring that the electrolyte is in a molten state and stable production. Therefore, the thickness of the furnace side is crucial to the thermal balance regulation of the electrolytic cell. In addition, since the furnace side is a solid after the molten electrolyte solidifies, its conductivity is almost zero, and the distribution of the furnace side directly affects the flow direction and distribution of the melt current. Especially on the cathode surface, if the furnace side formed is too thick, the horizontal current of the aluminum liquid layer will be larger and the stability of the magnetic fluid will be worse. At the same time, the cathode surface is prone to local current concentration, which is easy to cause the cathode sodium penetration and perforation; if the furnace side formed is too thin, it is easy to cause leakage and leakage of the side melt, reduce the current efficiency, and reduce the safety of the electrolytic cell operation.

[0003] In summary, the furnace wall plays an important role in the production and operation of aluminum electrolytic cells. Accurate prediction of the furnace wall distribution is conducive to analyzing and judging the operation status of the electrolytic cell, identifying the risk sources of the electrolytic cell in advance and taking effective adjustments and measures to promote the safe and stable operation of the aluminum electrolytic cell. However, due to the high temperature and high corrosion environment inside the electrolytic cell, it is difficult to predict the distribution of the furnace wall of the entire aluminum electrolytic cell through actual measurement, and it is even more impossible to measure the current density distribution of the melt and cathode surface under different furnace wall distribution conditions. Numerical simulation, as a soft measurement technology, can realize the prediction of furnace wall.

[0004] For the numerical simulation and prediction of furnace side, most of them use one-dimensional heat transfer deduction, two-dimensional or three-dimensional slice model to predict the furnace side. There are also 1 / 4 slot models established to predict the furnace side through the finite element method. However, these technologies and methods set the thermal conductivity of electrolyte and molten aluminum as constants, ignoring the influence of melt flow on the formation of furnace side. There is a big difference between the calculated and predicted furnace side and the actual full-slot three-dimensional furnace side.

[0005] The patent document with the authorization announcement number CN106202873B discloses a three-dimensional furnace wall evaluation method for aluminum electrolytic cells based on heat-flow coupling, which solves the furnace wall by taking electromagnetic force as the momentum source term and Joule heat as the energy source term under the premise of presetting the furnace wall. Although it takes into account the influence of melt flow on the distribution of the furnace wall, its Joule heat is calculated under the premise of presetting the furnace wall, and does not consider the influence of the furnace wall formation on the current distribution and Joule heat distribution. It does not realize the strong coupling calculation between electricity, heat, flow and furnace wall, which deviates from the actual working conditions, and cannot meet the joint prediction of furnace wall and current density distribution, and cannot meet the further demand for aluminum electrolytic cell design and process optimization. Summary of the invention

[0006] The purpose of the present invention is to provide a method, device, storage medium and product for calculating the furnace wall and current density of an aluminum electrolytic cell, so as to solve the problem that the traditional numerical simulation method deviates from the actual working conditions, resulting in a large difference between the predicted results and the actual ones.

[0007] The present invention solves the above technical problems through the following technical solutions: a method for calculating the furnace side and current density of an aluminum electrolytic cell, comprising:

[0008] Obtaining structural parameters and process parameters of the aluminum electrolytic cell; wherein the structural parameters include geometric dimensions and physical performance parameters;

[0009] According to the structural parameters and process parameters, an electro-magnetic coupling model of the conductive region is constructed, and based on the electro-magnetic coupling model of the conductive region, the electromagnetic force distribution of the electrolyte and the aluminum liquid region is calculated;

[0010] According to the structural parameters and process parameters, an anode bubble-electrolyte-aluminum liquid three-phase flow coupling model is constructed, and the bubble driving force distribution of the electrolyte and aluminum liquid regions is calculated based on the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model;

[0011] Constructing a three-dimensional model of an aluminum electrolytic cell according to the structural parameters and process parameters;

[0012] Using the electromagnetic force distribution and the bubble driving force distribution as momentum sources, a full-tank electric-thermal-fluid strong coupling model is constructed based on the three-dimensional model of the aluminum electrolysis cell;

[0013] According to the full-cell electrical-thermal-fluid strong coupling model, the furnace side and current density distribution of the aluminum electrolytic cell are calculated.

[0014] Furthermore, the control equation of the electro-magnetic coupling model is:

[0015]

[0016] in, represents the Nabla operator, represents the magnetic induction intensity of the conductive area, represents the current density in the conductive area, represents the magnetic field strength in the conductive area, η represents the magnetic permeability of the material, Represents the electromagnetic force formed by current density and magnetic induction intensity.

[0017] Furthermore, the control equation of the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model is:

[0018]

[0019] in, represents the Nabla operator, r i , i represent the flow rate, volume fraction and density of phase i, i represents the bubble phase, electrolyte phase or aluminum liquid phase, P i represents the pressure of phase i, represents the effective viscosity of phase i, T i represents the temperature of phase i, represents the external body force acting on phase i, M i represents the internal forces of other phases relative to phase i, represents the drag force of the bubble on the electrolyte, that is, the bubble driving force, represents the drag coefficient between the bubble and the electrolyte, d represents the equivalent diameter of the bubble, and r e represents the electrolyte volume fraction, ρ b represents the bubble density, represents the electrolyte flow rate, represents the bubble flow rate, τ represents the electrolyte surface tension coefficient, Δρ represents the density difference between the electrolyte and the bubble, Represents the acceleration due to gravity.

[0020] Furthermore, the control equation of the full-tank electrical-thermal-fluid strong coupling model is:

[0021]

[0022] in, represents the Nabla operator, σ represents the conductivity of the conductive area, represents the electric potential of the conductive area, represents the current density in the conductive area, S J represents the Joule heat of the conductive area, E represents the total thermal enthalpy of the calculation area, t represents the calculation time, Indicates the flow rate of electrolyte or aluminum liquid, λ eff represents the effective thermal conductivity of the electrolyte or aluminum liquid, T represents the temperature of the calculation area, ρ represents the density of the calculation area, Sr represents other thermal effects, e represents the sensible heat of the calculation area, δ represents the liquid phase volume fraction of the electrolyte or aluminum liquid, L represents the phase change latent heat of the electrolyte or aluminum liquid, T S Indicates the solidus temperature of the electrolyte or aluminum liquid, T L represents the liquidus temperature of the electrolyte or aluminum liquid, α represents the Prandtl number, C p represents the specific heat capacity of the calculation area, μ eff represents the effective viscosity of the electrolyte or aluminum liquid, μ represents the viscosity of the electrolyte or aluminum liquid, C μ represents a constant, k represents the turbulent kinetic energy of the electrolyte or aluminum liquid, ε represents the turbulent dissipation rate of the electrolyte or aluminum liquid, P represents the pressure of the electrolyte or aluminum liquid, represents the acceleration due to gravity, Represents the electromagnetic force formed by current density and magnetic induction intensity, represents the drag force of the bubble on the electrolyte, that is, the bubble driving force, Indicates the resistance to solidification, A mush represents the mushy zone constant, α k represents the reciprocal of the effective Prandtl number of k, G k represents the turbulent kinetic energy generated by the mean velocity gradient, α ε represents the reciprocal of the effective Prandtl number of ε, C 1ε Represents a constant, C 2ε Represents a constant.

[0023] Furthermore, the calculation method also includes verifying the full-tank electrical-thermal-fluid strong coupling model, specifically including:

[0024] Obtain the measured values ​​of furnace wall, flow field distribution, flow velocity distribution and tank shell temperature at multiple locations of the actual aluminum electrolytic cell;

[0025] Calculating the furnace wall and current density distribution of the actual aluminum electrolytic cell using the full-cell electrical-thermal-fluid strong coupling model;

[0026] The measured value and the calculated value are compared; when the deviation between the calculated value and the measured value exceeds a set threshold, the side heat dissipation coefficient of the full-slot electrical-thermal-fluid intensity coupling model is adjusted; when the deviation between the calculated value and the measured value exceeds a set threshold, a verified full-slot electrical-thermal-fluid intensity coupling model is obtained.

[0027] Furthermore, the calculation method also includes an evaluation step, specifically including:

[0028] The verified full-tank electrical-thermal-fluid strong coupling model is used to calculate the furnace sidewall and current density distribution under different working conditions;

[0029] The hot and cold states of the cell are evaluated based on the temperature field and the thickness of the furnace wall under different working conditions, and the risk of cathode damage is evaluated based on the current density distribution on the cathode surface.

[0030] Based on the same concept, the present invention also provides an electronic device, including a memory, a processor and a computer program / instructions stored in the memory, wherein the processor executes the computer program / instructions to implement the aluminum electrolysis cell furnace wall and current density calculation method as described above.

[0031] Based on the same concept, the present invention also provides a computer-readable storage medium on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the above-mentioned aluminum electrolysis cell furnace wall and current density calculation method is implemented.

[0032] Based on the same concept, the present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the aluminum electrolysis cell furnace side and current density calculation method as described above.

[0033] Beneficial Effects

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] The present invention utilizes a calculation method of strong electrical-thermal-fluid coupling, which can not only calculate the distribution state of the entire furnace wall, but also calculate the current density of the melt and the cathode carbon block surface in all directions due to the furnace wall distribution, and then analyze and judge the tank condition through the furnace wall distribution and the current density distribution; the present invention takes into account the large change in electrical conductivity before and after the furnace wall solidifies, which affects the current density and Joule heat distribution, and realizes strong coupling calculation and analysis among the electric field, thermal field, flow field and furnace wall, which is closer to industrial practice.

[0036] The full-cell electrical-thermal-current coupling model constructed by the present invention can directly calculate the dynamic changes of the furnace wall under transient changes in current and conduct risk assessment, and provide technical support for current intensification, flexible operation and other processes of aluminum electrolytic cells from the perspective of thermal management and thermal regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 The aluminum electrolytic cell furnace side and current density calculation method in the embodiment of the present invention;

[0039] Figure 2It is a three-dimensional structural model diagram of a 420kA aluminum electrolytic cell in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the distribution of the furnace side of a cross section of a 420kA aluminum electrolytic cell in an embodiment of the present invention;

[0041] Figure 4 Schematic diagram of the distribution of the furnace side of a 420kA aluminum electrolytic cell in the longitudinal section according to the embodiment of the present invention;

[0042] Figure 5 Schematic diagram of current density distribution in a longitudinal section of a 420kA aluminum electrolysis cell according to an embodiment of the present invention;

[0043] Figure 6 This is a comparison diagram of the calculated and measured furnace wall thickness of a 420kA aluminum electrolytic cell in an embodiment of the present invention;

[0044] Figure 7 It is a comparison diagram of the calculated and measured flow field distribution of a certain 420kA aluminum electrolytic cell in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0047] Example 1

[0048] like Figure 1 As shown, a method for calculating the furnace side and current density of an aluminum electrolytic cell provided by an embodiment of the present invention comprises the following steps:

[0049] Step 1: Obtain the structural parameters and process parameters of the aluminum electrolysis cell.

[0050] The structural parameters include geometric dimensions and physical performance parameters; wherein the geometric dimensions include the shape, length, width, height and coordinate position of the structural components such as the line, lining, anode group, cathode group, electrolyte and aluminum liquid layer, covering material, tank shell, etc. of the electrolytic cell. In this embodiment, a three-dimensional coordinate system is constructed with the length direction of the aluminum electrolytic cell as the X-axis, the width direction as the Y-axis, the height direction as the Z-axis, and the bottom midpoint of the end tank shell surface as the origin, and the coordinate position of the structural components is based on the three-dimensional coordinate system.

[0051] Physical performance parameters include electrical conductivity, thermal conductivity, magnetic permeability, specific heat capacity, density at different temperatures, and electrolyte physical performance parameters; the process of obtaining electrolyte physical performance parameters is: obtaining the chemical composition of the electrolyte, and further obtaining its physical performance parameters such as viscosity and phase change latent heat according to the chemical composition of the electrolyte. Process parameters include current intensity, electrolyte level, aluminum liquid level, cover material thickness and pole distance.

[0052] Taking a 420kA aluminum electrolytic cell as an example, its structural parameters are shown in Tables 1 to 3, and its structural diagram is shown in Figure 2 In order to distinguish the two faces in the length direction, Figure 2 The two faces in the length direction are marked as face A and face B; in order to present and analyze the calculation results later, the anode carbon blocks on face A and face B are numbered, A1~A12 are the anode carbon block numbers on face A, B1~B24 are the anode carbon block numbers on face B, 101 represents the covering material on face A, 102 represents the steel claw on face A, 103 represents the SiC / SiN brick on face A, 104 represents the cathode steel rod on face A, 105 represents the anode carbon block on face A, 106 represents the insulation brick on face A, 107 represents the high-strength castable on face A, 108 represents the high-strength castable on face A, and 109 represents the high-strength castable on face A. 109 represents the tamping paste on side A, 201 represents the cathode paste on side B, 202 represents the melt zone on side B, 203 represents the upper crust on side B, 204 represents the cathode carbon block on side B, 205 represents the insulation brick on side B, 206 represents the tamping paste on side B, 207 represents the dry waterproof material on side B, 208 represents the silicate cover plate on side B, 209 represents the ceramic fiber board on side B, 210 represents the refractory brick on side B, 211 represents the tank shell on side B, 212 represents the side carbon block on side B, and 213 represents the guide rod on side B.

[0053] Table 1 Geometrical parameters

[0054] Part Name Geometric size parameters (m) Guide rod 0.165×0.15×0.8 Steel Claws 0.165×1.185×0.455 Anode carbon block 0.66×1.7×0.39 Melt Zone 17.54×4.14×0.4 Cathode carbon block 0.665×1.84×0.485 Cathode steel rod 0.1×2.2×0.2 Covering material 1.754×4.14×0.33 Overall dimensions 17.812×4.352×2.688

[0055] Table 2 Physical performance parameters of solid parts (T represents temperature, X / Y / Z represents coordinate direction)

[0056]

[0057]

[0058] Table 3 Melt physical properties parameters (T represents temperature)

[0059]

[0060] Step 2: According to the structural parameters and process parameters in step 1, an electro-magnetic coupling model of the conductive region is constructed, and the electromagnetic force distribution of the electrolyte and the aluminum liquid region is calculated based on the electro-magnetic coupling model of the conductive region.

[0061] According to the structural parameters and process parameters in step 1, the electro-magnetic coupling model of the conductive area is constructed based on the finite element method. The specific construction process is as follows:

[0062] According to the structural parameters, a three-dimensional model of the conductive area including guide rods, steel claws, anode carbon blocks, electrolyte, aluminum liquid, cathode carbon blocks, cathode paste, cathode steel rods, column busbars, beam busbars and cathode busbars is constructed. The three-dimensional model of the conductive area is then imported into the Openfoam platform for meshing. Material properties are assigned to the meshed model according to the physical performance parameters of different components. The control equations of the electro-magnetic coupling model are then written through Openfoam, and finally the boundary conditions are loaded and solved.

[0063] In this embodiment, the boundary conditions of the electro-magnetic coupling model of the conductive region are voltage and current; the control equation of the electro-magnetic coupling model of the conductive region is:

[0064]

[0065] in, represents the Nabla operator, represents the magnetic induction intensity of the conductive area, represents the current density in the conductive area, represents the magnetic field strength in the conductive area, η represents the magnetic permeability of the material, Represents the electromagnetic force formed by current density and magnetic induction intensity.

[0066] Based on the constructed electro-magnetic coupling model of the conductive area, the electromagnetic force distribution in the electrolyte and aluminum liquid area is calculated by the finite element method. Taking a 420kA aluminum electrolytic cell as an example, some electromagnetic force distribution data are shown in Table 4.

[0067] Table 4 Partial electromagnetic force data

[0068]

[0069] In Table 4, X / Y / Z represent three coordinate directions. Represent the electromagnetic forces in the X, Y, and Z directions respectively.

[0070] Step 3: According to the structural parameters and process parameters in step 1, a three-phase flow coupling model of anode bubble-electrolyte-aluminum liquid is constructed, and the bubble driving force distribution in the electrolyte and aluminum liquid regions is calculated based on the three-phase flow coupling model of anode bubble-electrolyte-aluminum liquid.

[0071] According to the structural parameters and process parameters in step 1, a three-phase flow coupling model of anode bubble-electrolyte-aluminum liquid is constructed based on the finite volume method. The specific construction process is as follows:

[0072] A three-dimensional model of anode bubble-electrolyte-aluminum liquid is constructed according to the structural parameters, and then the three-dimensional model is imported into the Openfoam platform for meshing. Material properties are assigned to the meshed model according to the physical performance parameters of different components. The control equations of the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model are written through Openfoam, and finally the boundary conditions are loaded and solved.

[0073] In this embodiment, the boundary conditions of the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model are the bubble inlet and the bubble outlet; the control equation of the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model is:

[0074]

[0075] in, represents the Nabla operator, r i , i represent the flow rate, volume fraction and density of phase i, i represents the bubble phase, electrolyte phase or aluminum liquid phase, P i represents the pressure of phase i, represents the effective viscosity of phase i, T i represents the temperature of phase i, represents the external body force acting on phase i, M i represents the internal forces of other phases relative to phase i, represents the drag force of bubbles on the electrolyte (i.e., the bubble driving force), represents the drag coefficient between the bubble and the electrolyte, d represents the equivalent diameter of the bubble, and r e represents the electrolyte volume fraction, ρ b represents the bubble density, represents the electrolyte flow rate, represents the bubble flow rate, τ represents the electrolyte surface tension coefficient, Δρ represents the density difference between the electrolyte and the bubble, Represents the acceleration due to gravity.

[0076] Based on the constructed anode bubble-electrolyte-aluminum liquid three-phase flow coupling model, the driving force of the gas generation, flow and removal process at the bottom and side of the anode on the electrolyte and aluminum liquid is calculated by the finite element method, and the bubble driving force distribution of the entire electrolyte and aluminum liquid area is extracted. Taking a 420kA aluminum electrolytic cell as an example, the partial electromagnetic force distribution data of the entire electrolyte and aluminum liquid area are shown in Table 5.

[0077] Table 5 Partial bubble driving force data

[0078]

[0079]

[0080] In Table 5, X / Y / Z represent three coordinate directions. Represent the bubble driving force in the X, Y, and Z directions respectively.

[0081] Step 4: Based on the structural parameters and process parameters in step 1, a three-dimensional model of the aluminum electrolytic cell covering the entire cell structure is constructed.

[0082] Step 5: Using the electromagnetic force distribution and bubble driving force distribution as momentum sources, a full-cell electrical-thermal-fluid strong coupling model is constructed based on the finite volume method and the three-dimensional model of the aluminum electrolytic cell.

[0083] In this embodiment, the boundary conditions of the full-tank electric-thermal-fluid strong coupling model are voltage, current, ambient temperature, and the heat transfer coefficient between the aluminum electrolytic cell and the environment; the control equation of the full-tank electric-thermal-fluid strong coupling model is:

[0084]

[0085] in, represents the Nabla operator, σ represents the conductivity of the conductive area, represents the electric potential of the conductive area, represents the current density in the conductive area, S J represents the Joule heat of the conductive area, E represents the total thermal enthalpy of the calculation area, t represents the calculation time, represents the flow rate of electrolyte or aluminum liquid (for the solid area, this value is 0), λ eff represents the effective thermal conductivity of the electrolyte or aluminum liquid (for the solid area, this value is the thermal conductivity of the material itself), T represents the temperature of the calculation area, ρ represents the density of the calculation area, S r represents other thermal effects, e represents the sensible heat of the calculation area, δ represents the liquid phase volume fraction of the electrolyte or aluminum liquid, L represents the phase change latent heat of the electrolyte or aluminum liquid, T S Indicates the solidus temperature of the electrolyte or aluminum liquid, T L represents the liquidus temperature of the electrolyte or aluminum liquid, α represents the Prandtl number, C p represents the specific heat capacity of the calculation area, μ eff represents the effective viscosity of the electrolyte or aluminum liquid, μ represents the viscosity of the electrolyte or aluminum liquid, C μ represents a constant (specifically 0.0845), k represents the turbulent kinetic energy of the electrolyte or aluminum liquid, ε represents the turbulent dissipation rate of the electrolyte or aluminum liquid, P represents the pressure of the electrolyte or aluminum liquid, represents the acceleration due to gravity, Represents the electromagnetic force formed by current density and magnetic induction intensity, represents the drag force of the bubble on the electrolyte, that is, the bubble driving force, Indicates the resistance to solidification, A mushrepresents the mushy zone constant (specifically 10 5 ), α k represents the reciprocal of the effective Prandtl number of k, G k represents the turbulent kinetic energy generated by the mean velocity gradient, α ε represents the reciprocal of the effective Prandtl number of ε, C 1ε represents a constant (specifically 1.42), C 2ε represents a constant (specifically 1.68). Other thermal effects S r It includes alumina feeding heating, pole changing heating, electrochemical reaction endothermic heat, anode overvoltage heat, cathode overvoltage heat, bubble layer pressure drop heat and aluminum discharge heat.

[0086] Step 6: Calculate the furnace wall and current density distribution of the aluminum electrolytic cell based on the full-cell electrical-thermal-fluid strong coupling model.

[0087] The finite volume method is used to solve the control equation (3), and the furnace wall and current density distribution of the aluminum electrolytic cell are calculated to obtain the cross-sectional furnace wall distribution, longitudinal section furnace wall distribution and longitudinal section current density distribution. Taking a 420kA aluminum electrolytic cell as an example, the cross-sectional furnace wall distribution, longitudinal section furnace wall distribution and longitudinal section current density distribution are obtained as follows: Figures 3 to 5 As shown, Figure 3 and Figure 4 The numbers on the middle color band indicate the liquid volume fraction of the electrolyte or aluminum liquid. When the liquid volume fraction is 0, it indicates complete solidification; when the liquid volume fraction is 1, it indicates complete melting; when the liquid volume fraction is between 0 and 1, it indicates a mushy zone. Figure 4 The black streamlines with arrows in the figure indicate the direction of current flow. Figure 5 The numbers on the middle color band indicate the current density.

[0088] Step 7: Verify the full-tank electrical-thermal-fluid strong coupling model.

[0089] In order to ensure the accuracy of the full-tank electrical-thermal-fluid strong coupling model, the full-tank electrical-thermal-fluid strong coupling model is verified. The specific verification process is as follows:

[0090] Obtain the measured values ​​of the furnace wall, flow field distribution, flow velocity distribution and tank shell temperature at multiple positions of the actual aluminum electrolytic cell; calculate the furnace wall and current density distribution of the actual aluminum electrolytic cell using the full-cell electrical-thermal-fluid intensity coupling model; compare the measured values ​​with the calculated values; when the deviation between the calculated value and the measured value exceeds the set threshold, adjust the side heat dissipation coefficient of the full-cell electrical-thermal-fluid intensity coupling model; when the deviation between the calculated value and the measured value exceeds the set threshold, obtain the verified full-cell electrical-thermal-fluid intensity coupling model.

[0091] Step 8: Tank condition assessment.

[0092] The full-cell electrical-thermal-fluid intensity coupling model verified in step 7 is used to calculate the furnace wall and current density distribution under different working conditions; the hot and cold states of the cell are evaluated according to the temperature field and furnace wall thickness of the aluminum electrolytic cell under different working conditions, and the cathode damage risk is evaluated according to the current density distribution on the cathode surface.

[0093] Taking a 420kA aluminum electrolytic cell as an example, the verified full-cell electrical-thermal-fluid intensity coupling model is used to calculate the furnace wall, cell shell temperature and flow rate, and the calculated values ​​are compared with the measured values, as shown in Table 6 and Figure 6 As shown in Table 6, in general, the error is within 10%, which meets the requirements of industrial applications.

[0094] Table 6 Comparison of measured and calculated values

[0095]

[0096] Depend on Figure 6 It can be seen that the calculated value (or predicted value) of the furnace side is within the range of the test data, indicating the reliability of the full-tank electric-thermal-fluid strong coupling model constructed and verified by the present invention. Figure 7 The figure shows the flow field distribution comparison of a 420kA aluminum electrolytic cell calculated (or predicted) and measured (or tested). Figure 7 It can be seen that both the calculated and measured flow field morphologies show two vortices, and the flow velocity distribution sizes are relatively close, which further demonstrates the reliability of the full-tank electric-thermal-fluid strong coupling model constructed and verified by the present invention.

[0097] Depend on Figure 3 , Figure 4 and Figure 7 From the comparison, we can see that the thickness of the furnace side is greatly affected by the flow field shape. The greater the flow rate, the more serious the scouring of the furnace side, and the easier it is to bring heat from other places, making the furnace side thinner. The excessive flow rate leads to a thin furnace side, which easily causes the leakage slot to appear at the edge of the two vortices on the A and B sides. Targeted heat dissipation control is required at these locations to increase the uniformity of the furnace side thickness and ensure the stability of the aluminum electrolytic cell operation. Traditional technology cannot achieve this result.

[0098] Depend on Figure 4 and Figure 5It can be seen that the present invention can directly reflect the influence of the distribution of the furnace wall on the flow direction of the current in the melt area, and the current density distribution on the surface of the melt and the cathode carbon block. Specifically, the thicker the furnace wall, especially the position where the legs are stretched on the surface of the cathode carbon block, the greater the local current density, and the easier it is to promote the formation of cathode sodium penetration and perforation. Therefore, the electrolytic cell is prone to cathode damage mainly in the corners due to excessive current density on the cathode surface. Traditional technology cannot achieve this result, indicating the superiority of the present invention in realizing strong coupling calculation and analysis between electric field, thermal field, flow field and furnace wall, and is closer to industrial practice. The full-cell electric-thermal-current strong coupling model constructed by the present invention can also directly calculate the dynamic changes of the furnace wall under transient changes in current, and can further provide technical support for current intensification, flexible operation and other processes of aluminum electrolytic cells from the perspective of thermal management and thermal regulation.

[0099] Example 2

[0100] An embodiment of the present invention also provides an electronic device, which includes: a memory, a processor, and a computer program / instructions stored in the memory, and the processor executes the computer program / instructions to implement the aluminum electrolysis cell furnace side and current density calculation method in the embodiment of the present application.

[0101] Although not shown, the electronic device includes a processor, which can perform various appropriate operations and processes according to the program and / or data stored in the read-only memory (ROM) or the program and / or data loaded from the storage portion into the random access memory (RAM). The processor can be a multi-core processor, or it can include multiple processors. In some embodiments, the processor can include a general main processor and one or more special coprocessors, such as a central processing unit, a graphics processing unit (GPU), a neural network processor (NPU), a digital signal processor (DSP), etc. In RAM, various programs and data required for device operation are also stored. The processor, ROM and RAM are connected to each other via a bus. The input / output (I / O) interface is also connected to the bus.

[0102] The processor and memory are used together to execute the program / instructions stored in the memory. When the program / instructions are executed by the computer, the methods, steps or functions described in the above embodiments can be implemented.

[0103] Although not shown, an embodiment of the present invention further provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the aluminum electrolysis cell furnace side and current density calculation method in the embodiment of the present application.

[0104] Readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0105] Although not shown, an embodiment of the present invention further provides a computer program product, including: a computer program / instruction, which, when executed by a processor, implements the aluminum electrolysis cell furnace side and current density calculation method in the embodiment of the present application.

[0106] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A method for calculating the furnace side and current density of an aluminum electrolytic cell, characterized in that: The calculation method includes: Obtaining structural parameters and process parameters of the aluminum electrolytic cell; wherein the structural parameters include geometric dimensions and physical performance parameters; According to the structural parameters and process parameters, an electro-magnetic coupling model of the conductive region is constructed, and based on the electro-magnetic coupling model of the conductive region, the electromagnetic force distribution of the electrolyte and the aluminum liquid region is calculated; According to the structural parameters and process parameters, an anode bubble-electrolyte-aluminum liquid three-phase flow coupling model is constructed, and the bubble driving force distribution of the electrolyte and aluminum liquid regions is calculated based on the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model; Constructing a three-dimensional model of an aluminum electrolytic cell according to the structural parameters and process parameters; Using the electromagnetic force distribution and the bubble driving force distribution as momentum sources, a full-tank electric-thermal-fluid strong coupling model is constructed based on the three-dimensional model of the aluminum electrolysis cell; According to the full-cell electrical-thermal-fluid strong coupling model, the furnace side and current density distribution of the aluminum electrolytic cell are calculated.

2. The method for calculating the furnace side and current density of an aluminum electrolytic cell according to claim 1, characterized in that: The control equation of the electro-magnetic coupling model is: in, represents the Nabla operator, represents the magnetic induction intensity of the conductive area, represents the current density in the conductive area, represents the magnetic field strength in the conductive area, η represents the magnetic permeability of the material, Represents the electromagnetic force formed by current density and magnetic induction intensity.

3. The method for calculating the furnace side and current density of an aluminum electrolytic cell according to claim 1, characterized in that: The control equation of the anode bubble-electrolyte-aluminum liquid three-phase flow coupling model is: in, represents the Nabla operator, r i , i represent the flow rate, volume fraction and density of phase i, i represents the bubble phase, electrolyte phase or aluminum liquid phase, P i represents the pressure of phase i, represents the effective viscosity of phase i, T i represents the temperature of phase i, represents the external body force acting on phase i, M i represents the internal forces of other phases relative to phase i, represents the drag force of the bubble on the electrolyte, that is, the bubble driving force, represents the drag coefficient between the bubble and the electrolyte, d represents the equivalent diameter of the bubble, and r e represents the electrolyte volume fraction, ρ b represents the bubble density, represents the electrolyte flow rate, represents the bubble flow rate, τ represents the electrolyte surface tension coefficient, Δρ represents the density difference between the electrolyte and the bubble, Represents the acceleration due to gravity.

4. The method for calculating the furnace side and current density of an aluminum electrolytic cell according to claim 1, characterized in that: The control equation of the full-tank electrical-thermal-fluid strong coupling model is: E=e+δL, l eff =αC p m eff , in, represents the Nabla operator, σ represents the conductivity of the conductive area, represents the electric potential of the conductive area, represents the current density in the conductive area, S J represents the Joule heat of the conductive area, E represents the total thermal enthalpy of the calculation area, t represents the calculation time, Indicates the flow rate of electrolyte or aluminum liquid, λ eff represents the effective thermal conductivity of the electrolyte or aluminum liquid, T represents the temperature of the calculation area, ρ represents the density of the calculation area, S r represents other thermal effects, e represents the sensible heat of the calculation area, δ represents the liquid phase volume fraction of the electrolyte or aluminum liquid, L represents the phase change latent heat of the electrolyte or aluminum liquid, T S Indicates the solidus temperature of the electrolyte or aluminum liquid, T L represents the liquidus temperature of the electrolyte or aluminum liquid, α represents the Prandtl number, C p represents the specific heat capacity of the calculation area, μ eff represents the effective viscosity of the electrolyte or aluminum liquid, μ represents the viscosity of the electrolyte or aluminum liquid, C μ represents a constant, k represents the turbulent kinetic energy of the electrolyte or aluminum liquid, ε represents the turbulent dissipation rate of the electrolyte or aluminum liquid, P represents the pressure of the electrolyte or aluminum liquid, represents the acceleration due to gravity, Represents the electromagnetic force formed by current density and magnetic induction intensity, represents the drag force of the bubble on the electrolyte, that is, the bubble driving force, Indicates the resistance to solidification, A mush represents the mushy zone constant, α k represents the reciprocal of the effective Prandtl number of k, G k represents the turbulent kinetic energy generated by the mean velocity gradient, α ε represents the reciprocal of the effective Prandtl number of ε, C 1ε Represents a constant, C 2ε Represents a constant.

5. The aluminum electrolysis cell furnace side and current density calculation method according to any one of claims 1 to 4, characterized in that: The calculation method also includes verifying the full-tank electrical-thermal-fluid strong coupling model, specifically including: Obtain the measured values ​​of furnace wall, flow field distribution, flow velocity distribution and tank shell temperature at multiple locations of the actual aluminum electrolytic cell; Calculating the furnace wall and current density distribution of the actual aluminum electrolytic cell using the full-cell electrical-thermal-fluid strong coupling model; The measured value and the calculated value are compared; when the deviation between the calculated value and the measured value exceeds a set threshold, the side heat dissipation coefficient of the full-slot electrical-thermal-fluid intensity coupling model is adjusted; when the deviation between the calculated value and the measured value exceeds a set threshold, a verified full-slot electrical-thermal-fluid intensity coupling model is obtained.

6. The method for calculating the furnace side and current density of an aluminum electrolytic cell according to claim 5, characterized in that: The calculation method further includes an evaluation step, specifically comprising: The verified full-tank electrical-thermal-fluid strong coupling model is used to calculate the furnace sidewall and current density distribution under different working conditions; The hot and cold states of the cell are evaluated based on the temperature field and the thickness of the furnace wall under different working conditions, and the risk of cathode damage is evaluated based on the current density distribution on the cathode surface.

7. An electronic device comprising a memory, a processor, and a computer program / instruction stored in the memory, characterized in that: The processor executes the computer program / instructions to implement the aluminum electrolysis cell furnace side and current density calculation method according to any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the aluminum electrolysis cell furnace side and current density calculation method as described in any one of claims 1 to 6 are implemented.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the aluminum electrolysis cell furnace side and current density calculation method as described in any one of claims 1 to 6 are implemented.

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