Numerical simulation and optimization analysis method of multi-stage rotary disk solid continuous washing equipment

Abstract

The present invention discloses a numerical simulation and optimization analysis method for a multi-stage rotary disk solid continuous washing device, belonging to the technical field of washing devices and washing methods. The method comprises the following steps: Step S1: determining the structural parameters and process parameters that affect the comprehensive washing efficiency of the device; Step S2: selecting a number of factors to be evaluated from the structural parameters and process parameters based on theoretical derivation and engineering experience; Step S3: determining an evaluation model for the comprehensive washing efficiency; Step S4: conducting an orthogonal experimental design and designing an orthogonal experimental factor level table; Step S5: conducting numerical simulation calculations; Step S6: conducting orthogonal analysis on the numerical simulation calculation results to analyze and evaluate the influence of the factors to be evaluated; Step S7: determining and finding a parameter combination that conforms to theoretical calculations or outperforms engineering experience. The method can accurately, efficiently, quickly, and cost-effectively determine the optimal structural and process parameter combination for a solid continuous washing device.

Description

Technical Field

[0001] The present invention belongs to the technical field of washing equipment and washing methods, and in particular relates to a numerical simulation and optimization analysis method for a multi-stage rotary disk type solid continuous washing equipment. Background Art

[0002] In the chemical industry, solid washing refers to the process of washing various raw materials through liquid contact after a series of reactions to remove impurities such as raw materials and by-products attached to or wrapped in the solid surface and between particles, thereby achieving the following effects, including: improving product purity to meet the needs of subsequent production, recycling raw materials to improve economic benefits, etc.

[0003] The comprehensive washing efficiency of the solid continuous washing equipment is determined by factors such as washing effect, stirring power density, and solid retention in the tower; among them, washing effect refers to the degree of solid cleaning, and the evaluation criteria include the residual amount of liquid phase impurities (to evaluate the degree of liquid phase impurity removal) and the average residence time of particles (to evaluate the degree of soluble solid phase impurity removal); stirring power density refers to the power consumed per unit volume of the solid continuous washing equipment; solid retention in the tower refers to the amount of macroscopic solid materials retained in the washing tower after the continuous washing equipment has stabilized (microscopic particles will be updated and flow out of the tower over time); the comprehensive washing efficiency of the aforementioned solid continuous washing equipment will be affected by the structural parameters and process parameters of the washing equipment.

[0004] In order to improve the washing effect of solid continuous washing equipment per unit volume and per unit time, multi-stage turntable solid continuous washing equipment is currently used to enhance the solid-liquid contact area or contact time. However, when the multi-stage turntable solid continuous washing equipment is applied to different types of industrial production, there is a lack of research on the changing rules of the washing effect and solid processing capacity with the structure and process parameters of the washing equipment. This is not conducive to the promotion and application of the multi-stage turntable solid continuous washing equipment, nor is it conducive to maximizing the comprehensive washing efficiency when the multi-stage turntable solid continuous washing equipment is applied to different types of industrial production. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, promote the design optimization of multi-stage rotary disk type solid continuous washing equipment, maximize the comprehensive washing efficiency, and improve economic benefits, the present invention provides a numerical simulation and optimization analysis method for multi-stage rotary disk type solid continuous washing equipment, including the following steps:

[0006] Step S1: Determine the structural parameters and process parameters that affect the comprehensive washing efficiency of the multi-stage rotary disc type solid continuous washing equipment based on engineering experience;

[0007] Step S2: Based on theoretical deduction, select several factors to be evaluated from the structural parameters and the process parameters;

[0008] Step S3: constructing an evaluation model for the comprehensive washing efficiency of a multi-stage rotary disk type solid continuous washing equipment;

[0009] Step S4: Design an orthogonal experimental factor level table based on the factors to be evaluated selected in step S2;

[0010] Step S5: Conducting a three-dimensional model of the multi-stage rotary disc type solid continuous washing equipment, establishing a fluid calculation domain model of the equipment in a liquid-filled state, and conducting numerical simulation calculations;

[0011] Step S6: performing orthogonal analysis on the results obtained from the numerical simulation calculation in step S5, and evaluating the influence of the factors to be evaluated on the comprehensive washing efficiency of the multi-stage rotary disc type solid continuous washing equipment;

[0012] Step S7: Determine whether there is a combination of the structural parameters and the process parameters that is consistent with theoretical calculations or better than engineering experience. If so, output the optimization analysis results; if not, jump to step S4, redesign the orthogonal experiment, and adjust the level range of each factor until a combination of the structural parameters and the process parameters that is consistent with theoretical calculations or better than engineering experience is found.

[0013] Furthermore, the structural parameters include the single-layer height, turntable paddle diameter, turntable paddle height, turntable diameter and annular partition opening diameter of the multi-stage turntable type solid continuous washing equipment; the process parameters include: the material feed rate, detergent feed rate and turntable speed of the multi-stage turntable type solid continuous washing equipment.

[0014] Furthermore, the evaluation model adopts a weighted factor evaluation model based on the hierarchical analysis method, and the evaluation parameters of the evaluation model include: liquid phase impurity volume fraction distribution, average particle residence time, stirring power density and solid retention in the tower.

[0015] Furthermore, the numerical simulation calculation in step S5 is based on Siemens STAR CCM+ software, and the specific numerical simulation calculation method includes the following steps:

[0016] Step S51: Equipment Simplification and Model Construction: The multi-stage rotary disk type continuous solid washing equipment is simplified, and the equipment components included in the simplified multi-stage rotary disk type continuous solid washing equipment are three-dimensionally modeled to obtain a three-dimensional model of the multi-stage rotary disk type continuous solid washing equipment; the structural parameters of the equipment components are adjusted according to the orthogonal experimental factor level table in step S4; and a fluid calculation domain model of the multi-stage rotary disk type continuous solid washing equipment in a liquid-filled state is established based on the three-dimensional model of the multi-stage rotary disk type continuous solid washing equipment;

[0017] Step S52: Importing a geometric model and defining boundaries: Importing the fluid calculation domain model file of the multi-stage rotary disk solid continuous washing equipment in the liquid-filled state into the Siemens STAR CCM+ software, and defining the boundaries and names of the fluid calculation domain model according to the software requirements;

[0018] Step S53: Boundary type setting and meshing: setting boundary condition types for the fluid calculation domain model with completed boundary definition and performing meshing;

[0019] Step S54: Making physical assumptions: The numerical simulation calculation is based on the following basic assumptions: assuming that the solid particles have the same diameter and that there is no agglomeration between the particles; ignoring the energy consumed by the solid particles during the collision and rebound process in the multi-stage rotary disk type continuous solid washing equipment; assuming that the components in the multi-stage rotary disk type continuous solid washing equipment will not be worn by the solid particles;

[0020] Step S55: Setting the physical calculation model: Based on the software requirements used by the fluid calculation domain model, define the physical continuum for numerical simulation calculation and the physical calculation model used. The physical calculation model settings include: continuous phase turbulence model, Lagrangian phase discrete model, and material properties of the calculation medium;

[0021] Step S56: Setting boundary condition values: setting boundary condition values ​​of the continuous phase and the discrete phase, respectively, according to actual process parameters;

[0022] Step S57: Run numerical simulation calculation: Run numerical simulation calculation to obtain numerical simulation results of the performance of the multi-stage rotary disc type solid continuous washing equipment, and use them as subsequent evaluation parameters.

[0023] Furthermore, when performing the three-dimensional modeling operation on the equipment components in step S51, the set parameters include: the geometric shape and geometric size parameters of the turntable and the annular partition, and the position and opening diameter of the material and detergent inlet and outlet.

[0024] Furthermore, in step S53, the boundary condition type of the fluid calculation domain model is set to include: the inlet boundary type is a mass flow inlet, and the outlet boundary type is an outlet with a specified mass flow;

[0025] Meshing the fluid computational domain model includes: setting the mesh of the fluid computational domain to use a polyhedron unstructured mesh; performing local mesh encryption on the turntable wall, interface, annular partition, and baffle wall; and generating a prismatic boundary layer mesh on the surface of each wall.

[0026] Furthermore, in step S55, the setting of the physical calculation model specifically includes:

[0027] Set the direction of gravity acceleration according to the placement of the multi-stage rotary disk type solid continuous washing equipment;

[0028] The continuous phase turbulence model adopts the K-Epsilon two-layer model based on the Reynolds time-averaged method;

[0029] The solver uses implicit unsteady solver and separated flow solver for transient solution, and the discretization format uses second-order upwind format;

[0030] Create a continuous phase, Lagrangian phase, or discrete phase for each material based on actual industrial production, and set the material properties of each continuous phase separately, including density and dynamic viscosity;

[0031] Create a Lagrangian phase, select a constant density material particle model, a residence time model, a two-way coupling model, and a turbulent dissipation model;

[0032] Material properties of the discrete phase are set, the material properties including density.

[0033] Furthermore, in step S56, the numerical values ​​of each boundary condition of the continuous phase and the numerical values ​​of each boundary condition of the discrete phase are set according to the parameters designed in the orthogonal experimental factor level table, wherein the numerical values ​​of each boundary condition of the continuous phase include: mass flow rate, phase volume fraction; the numerical values ​​of each boundary condition of the discrete phase include: particle size, particle mass flow rate, particle flow velocity, and particle distribution mode.

[0034] Furthermore, the step S57 includes:

[0035] Step S571: Continuous phase simulation calculation: The Lagrangian phase solver is frozen, and the multi-stage rotary disk solid continuous washing equipment operates in a continuous phase state; the mass flow rate and phase volume fraction at each inlet and outlet section of the continuous phase are monitored. When the fluctuation of the monitored quantities does not exceed the preset fluctuation range and the fluctuation of the calculated residual is stable, it is determined that the continuous phase calculation has reached a stable state, and the process jumps to step S572;

[0036] Step S572: discrete phase simulation calculation: enable the Lagrangian phase solver, and the discrete phase enters the multi-stage rotary disk type solid continuous washing equipment; monitor the average residence time of particles in the outlet area of ​​the multi-stage rotary disk type solid continuous washing equipment. When the fluctuation of the monitored amount does not exceed the preset fluctuation range and the calculated residual fluctuation is stable, it is determined that the discrete phase calculation has reached a stable state, the numerical simulation calculation is terminated, and the numerical simulation calculation results are obtained. The numerical simulation results include: the liquid phase impurity content at the material outlet, the average residence time of the particles, the stirring power density, and the solid retention in the tower.

[0037] Furthermore, the calculation time step of the continuous phase simulation calculation is 0.1-0.5s; the calculation time step of the discrete phase simulation calculation is set according to a formula, and the formula makes the discrete phase particle movement conform to the particle movement distance within a single time step conform to a preset value.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention can simulate the effects of different structural and process parameters of a multi-stage rotary disk continuous solid washing device on its overall washing efficiency, facilitating accurate, efficient, rapid, and cost-effective determination of the optimal structural and process parameter combination for the multi-stage rotary disk continuous solid washing device.

[0040] 2. The numerical simulation and optimization analysis method of the present invention is highly versatile and has certain guiding significance for the structural and process optimization design of multi-stage rotary disk solid continuous washing equipment, and can provide reference and data support for related structural design and process optimization;

[0041] 3. The numerical simulation and optimization analysis method of the present invention provides a simplified analysis method based on orthogonal experimental design for the physical process characteristics of the multi-stage turntable type solid continuous washing equipment, adopts the Euler-Lagrange method for modeling and numerical simulation calculations, and proposes corresponding process schemes in the steps of grid division, numerical simulation calculations, etc., which reduces the data calculation and processing amount of the numerical simulation calculation in the technical solution of the present invention and improves the accuracy of the numerical simulation calculation, thereby realizing the efficient, rapid and accurate determination of the optimal structure and process parameter combination of the multi-stage turntable type solid continuous washing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of a flow chart of an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of a fluid calculation domain model according to an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of mesh division of a fluid computational domain according to an embodiment of the present invention;

[0045] Figure 4 This is a cloud diagram of the volume fraction distribution of the acetone phase according to one embodiment of the present invention;

[0046] Figure 5 A particle residence time distribution cloud diagram and particle distribution according to an embodiment of the present invention (colors in the diagram represent values, and colors are not shown in the diagram);

[0047] Figure 6 This is a statistical diagram of particle residence time according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0049] Example 1

[0050] There is a multi-stage rotary disc continuous solid washing equipment used for washing slurry containing polyarylene sulfide (PPS) particles. The purpose of washing is to remove acetone in the slurry and soluble impurities attached to the surface and gaps of the particles. Numerical simulation and optimization analysis are now carried out on this multi-stage rotary disc continuous solid washing equipment.

[0051] like Figure 1 As shown, the present invention provides a numerical simulation and optimization analysis method for a multi-stage rotary disk type solid continuous washing device, comprising the following steps:

[0052] Step S1: Based on actual industrial production requirements and engineering experience, the modifiable structural parameters affecting the comprehensive washing efficiency of the target multi-stage rotary disc type solid continuous washing equipment are determined as follows: rotary disc paddle diameter, rotary disc diameter, and annular baffle opening diameter; the modifiable process parameters are determined as follows: detergent feed rate and rotary disc speed;

[0053] Step S2: Based on theoretical derivation and engineering experience, the annular baffle opening diameter, detergent feed rate, and turntable speed are selected as the main factors affecting the comprehensive washing efficiency of the target multi-stage turntable solid continuous washing equipment, and the above main factors are used as the factors to be evaluated;

[0054] Step S3: Based on the PPS particle slurry characteristics and washing process requirements, a weighted factor evaluation model for the comprehensive washing efficiency of the multi-stage rotary disc type solid continuous washing equipment is determined based on the AHP analytical hierarchy process. The evaluation parameters include four items: liquid phase impurity content, average particle residence time, stirring power density, and solid retention in the tower. The specific evaluation formula is shown below:

[0055] U=Na×A+Nb×B+Nc×C+Nd×D (1)

[0056] Among them, A is the score of liquid impurity content at the material outlet, B is the score of average particle residence time, C is the score of stirring power density, and D is the score of solid retention in the tower; Ni is the score weight obtained based on the AHP hierarchical analysis method, and the corresponding values ​​are as follows:

[0057] Table 1 Scoring weight table

[0058] Na Nb Nc Nd 4.77％ 47.74％ 28.23％ 19.26％

[0059] U is the comprehensive washing efficiency score of the multi-stage rotary disk solid continuous washing equipment, and each score is the result of normalizing the four evaluation parameters to [0,1] and then mapping them to [1,10] according to the negative-positive relationship;

[0060] Step S4: Based on the main factors affecting the comprehensive washing efficiency of the target multi-stage rotary disk type solid continuous washing equipment being determined as the factors to be evaluated, each factor to be evaluated is considered at three levels, and an orthogonal experimental factor level table is designed, as shown in Table 2:

[0061] Table 2 Orthogonal test factor level table

[0062]

[0063] According to the 3x3 orthogonal experimental design rules, 9 groups of representative experiments were designed, as shown in Table 3:

[0064] Table 3 Orthogonal test plan

[0065]

[0066]

[0067] Step S5: Using Siemens NX software to perform three-dimensional modeling of the equipment components of the multi-stage rotary disk solid continuous washing equipment, and using Siemens STAR CCM+ software to perform numerical simulation, specifically including the following steps:

[0068] Step S51: Simplifying the multi-stage rotary disk type continuous solid washing equipment, using 3D modeling software to perform 3D modeling operations on simplified equipment components of the multi-stage rotary disk type continuous solid washing equipment, such as the rotary disk, annular baffle, and material and detergent inlet and outlet components. The set parameters include: the geometric shape and geometric size parameters of the rotary disk and annular baffle, and the position and opening diameter of the material and detergent inlet and outlet;

[0069] The diameter of the annular baffle opening is determined according to the orthogonal test scheme described in Table 3;

[0070] Subsequently, the fluid calculation domain model was extracted from the three-dimensional model of the multi-stage rotary disk solid continuous washing equipment. The completed fluid calculation domain model is as follows: Figure 2 As shown in the figure, the three fluid calculation domain models corresponding to different annular baffle opening diameters are saved as .x_t format files respectively;

[0071] Step S52: Import the exported .x_t format file into Siemens STAR CCM+ software, and define the inlet and outlet boundaries, interface boundaries, wall boundaries, and names of the fluid calculation domain model in the "Geometry-Component" node;

[0072] Step S53: Assign the fluid computational domain model with completed boundary definition to the "Region" node, and then in the "Region-Boundary" node, set the inlet boundary type of the fluid computational domain to the "Mass Flow Inlet" boundary, and the outlet boundary type to the "Outlet" boundary with a specified mass flow rate;

[0073] Go back to the "Geometry - Operations - Auto Mesh" node and mesh the aforementioned fluid computational domain. To balance the accuracy of the numerical simulation results with computational efficiency, use polyhedral meshes for unstructured meshing of the fluid computational domain. Local mesh refinement is performed on the turntable wall, interface, annular partition, and baffle wall to ensure a minimum mesh quality of no less than 0.4.

[0074] The local grid size is 1 / 4 of the overall grid. At the same time, a prismatic boundary layer grid with a total thickness of 2 mm and a total of 3 layers is generated on the surface of each wall, and Wall Y+ is guaranteed to be greater than 35 to meet the simulation calculation requirements. The divided grid is as follows Figure 3 As shown;

[0075] Step S54: During the numerical simulation calculation, the following physical assumptions are made:

[0076] ① Assume that the solid particles have the same diameter and there is no agglomeration between the particles;

[0077] ② Ignore the energy consumed by solid particles during collision and rebound in the multi-stage rotary disc solid continuous washing equipment;

[0078] ③ Assume that the components in the multi-stage rotary disc solid continuous washing equipment will not be worn by solid particles;

[0079] Step S55: In the "Continuum-Model" node, the physical calculation model for the numerical simulation calculation is set in detail as follows;

[0080] ① Enable the "Gravity" model. According to the placement of the target multi-stage rotary disk solid continuous washing equipment, the Z direction is set to -9.81m / s2, and the X and Y directions are set to 0m / s2.

[0081] ② The turbulence model uses the "realizable K-Epsilon two-layer model" based on the "Reynolds time-averaged method"

[0082] ③ The solver uses an implicit unsteady solver and a separated flow solver for transient solutions, and the discrete format uses a second-order upwind format to improve solution accuracy;

[0083] ④ Enable the Mixed Multiphase (MMP) model. In the Multiphase - Euler Phase node, create a water phase corresponding to the detergent and an acetone phase corresponding to the material solvent. Select the Liquid and Constant Density models, and set the density and dynamic viscosity of the water and acetone phases, respectively.

[0084] ⑤ Enable the "Lagrangian Phase" model, create a particle phase corresponding to the PPS particles in the "Lagrangian Phase" node, select constant density, material particles, residence time, bidirectional coupling and turbulent dissipation model, and set the density of the particle phase;

[0085] Step S56: According to the actual process parameters and the orthogonal test scheme described in Table 3, the boundary condition values ​​of the continuous Euler phase and the discrete particle phase are set at the "Region-Boundary" node and the "Ejector" node respectively; wherein the setting parameters of the continuous phase include: mass flow rate, phase volume fraction, as shown in Table 4:

[0086] Table 4 Numerical settings of continuous phase boundary conditions

[0087]

[0088] The setting parameters of the discrete phase include: particle size, particle mass flow rate, particle flow rate, and particle distribution mode, as shown in Table 5:

[0089] Table 5 Numerical settings of discrete phase boundary conditions

[0090]

[0091] Step S57: Run numerical simulation calculations to obtain the performance parameters of the target multi-stage rotary disc type solid continuous washing equipment for the nine orthogonal test schemes, including the liquid phase impurity content at the material outlet, the average particle residence time, the stirring power density, and the solid retention in the tower; Figure 4 The acetone phase volume fraction distribution cloud diagram shown, Figure 5 The particle residence time distribution cloud diagram and particle distribution shown in the figure are as follows: Figure 6 Particle residence time statistics shown;

[0092] The numerical simulation calculation adopts the following steps to ensure the calculation accuracy and improve the calculation efficiency, including:

[0093] Step S571: Continuous phase simulation calculation: The Lagrangian phase solver is frozen, and the multi-stage rotary disk solid continuous washing equipment is operated in a pure continuous phase state; the mass flow rate and phase volume fraction at each inlet and outlet section of the continuous phase are monitored. When the fluctuation of the monitored quantity does not exceed ±2% and the fluctuation of the calculated residual error is stable, it is determined that the continuous phase calculation has reached a stable state;

[0094] Step S572: Discrete Phase Simulation Calculation: The Lagrangian phase solver is activated, and the discrete phase enters the multi-stage rotary disk continuous solid washing equipment according to the boundary conditions of the "Ejector" node. The average residence time of particles in the outlet area of ​​the multi-stage rotary disk continuous solid washing equipment is monitored. When the fluctuation of the monitored value does not exceed ±2% and the fluctuation of the calculated residual error is stable, the discrete phase calculation is determined to have reached a stable state, and the numerical simulation calculation ends.

[0095] Performing numerical simulation calculations for the continuous phase and discrete phase in steps can avoid the problem that the discrete phase calculation converges while the continuous phase calculation has not yet converged;

[0096] Step S6: Using the range method and the multi-factor variance method, an orthogonal analysis is conducted on the performance parameters of the multi-stage rotary disk type continuous solid washing equipment; and based on the evaluation model of the comprehensive washing efficiency of the multi-stage rotary disk type continuous solid washing equipment, the weighted factor score of each scheme is obtained, as shown in Table 6:

[0097] Table 6 Scoring of each scheme

[0098]

[0099]

[0100] Among them, column A is the score of the liquid phase impurity content at the material outlet, column B is the score of the average residence time of the particles, column C is the score of the stirring power density, column D is the score of the solid retention in the tower, and column U is the total score of each scheme calculated according to formula (1).

[0101] Step S7: Determine whether there is a parameter combination that is consistent with theoretical calculations or better than engineering experience. If so, the optimization analysis process ends; if not, jump to step S4, redesign the orthogonal experiment, and adjust the level range of each factor until a parameter combination that is consistent with theoretical calculations or better than engineering experience is found.

[0102] In this embodiment, according to Table 6, among the 9 orthogonal experimental schemes, Scheme 1 (partition through-hole diameter 95 mm, rotation speed 35 rpm, detergent flow rate 300 kg / h) is the optimal parameter combination among the 9 orthogonal experimental schemes.

[0103] Example 2

[0104] As a preferred approach, in some embodiments of the present invention, in step S571: during the continuous phase simulation calculation process, the calculation time step may be a larger value of 0.1 s to save calculation time;

[0105] As a preferred method, in step S572: during the discrete phase simulation calculation, the calculation time step is set and determined according to the following formula: the particle movement distance within a single time step does not exceed 5 grid geometric dimensions, that is, the Courant number CFL = UkeliΔt / Δx≤5, where Ukeli is the particle flow velocity, Δt is the time step, and Δx is the grid geometric dimension.

[0106] This embodiment performs numerical simulation calculations on the continuous phase and the discrete phase in steps. While ensuring the convergence of the calculation, the larger time step used in the continuous phase calculation is beneficial to reducing the time consumption of the overall numerical simulation calculation.

[0107] In this embodiment, the continuous phase calculation uses a time step of 0.1 s, which consumes 350 time steps; the discrete phase calculation uses a time step of 0.001 s;

[0108] By adopting the technical solution of this embodiment, the calculation speed of the continuous phase is increased by 100 times within the corresponding 35s physical time, and the time consumption of the overall calculation (corresponding to 350s physical time) is reduced to 90% when the time step is not adjusted.

[0109] The above description describes the basic principles and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above embodiments and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be included in the present invention, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

Claims

1. A numerical simulation and optimization analysis method for a multi-stage rotary disk solid continuous washing equipment, characterized by: The steps include: Step S1: Determine the structural parameters and process parameters that affect the comprehensive washing efficiency of the multi-stage rotary disc type solid continuous washing equipment based on engineering experience; Step S2: Based on theoretical deduction, select several factors to be evaluated from the structural parameters and the process parameters; Step S3: constructing an evaluation model for the comprehensive washing efficiency of a multi-stage rotary disk type solid continuous washing equipment; Step S4: Design an orthogonal experimental factor level table based on the factors to be evaluated selected in step S2; Step S5: Conducting a three-dimensional model of the multi-stage rotary disc type solid continuous washing equipment, establishing a fluid calculation domain model of the equipment in a liquid-filled state, and conducting numerical simulation calculations; Step S6: performing orthogonal analysis on the results obtained from the numerical simulation calculation in step S5, and evaluating the influence of the factors to be evaluated on the comprehensive washing efficiency of the multi-stage rotary disc type solid continuous washing equipment; Step S7: Determine whether there is a combination of the structural parameters and the process parameters that is consistent with theoretical calculations or better than engineering experience. If so, output the optimization analysis results. If not, jump to step S4, redesign the orthogonal experiment, and adjust the level range of each factor until a combination of the structural parameters and the process parameters that is consistent with theoretical calculations or better than engineering experience is found. The evaluation model adopts a weighted factor evaluation model based on the hierarchical analysis method. The evaluation parameters of the evaluation model include: liquid phase impurity volume fraction distribution, average particle residence time, stirring power density and solid retention in the tower. The specific evaluation formula is as follows: U=Na×A+Nb×B+Nc×C+Nd×D Among them, A is the score of liquid impurity content at the material outlet, B is the score of average particle residence time, C is the score of stirring power density, and D is the score of solid retention in the tower; Ni is the score weight obtained based on AHP. The numerical simulation calculation in step S5 is based on Siemens STAR CCM+ software, and the specific numerical simulation calculation method includes the following steps: Step S51: Equipment Simplification and Model Construction: The multi-stage rotary disk type continuous solid washing equipment is simplified, and the equipment components included in the simplified multi-stage rotary disk type continuous solid washing equipment are three-dimensionally modeled to obtain a three-dimensional model of the multi-stage rotary disk type continuous solid washing equipment; the structural parameters of the equipment components are adjusted according to the orthogonal experimental factor level table in step S4; and a fluid calculation domain model of the multi-stage rotary disk type continuous solid washing equipment in a liquid-filled state is established based on the three-dimensional model of the multi-stage rotary disk type continuous solid washing equipment; Step S52: Importing a geometric model and defining boundaries: Importing the fluid calculation domain model file of the multi-stage rotary disk solid continuous washing equipment in the liquid-filled state into the Siemens STAR CCM+ software, and defining the boundaries and names of the fluid calculation domain model according to the software requirements; Step S53: Boundary type setting and meshing: setting boundary condition types for the fluid calculation domain model with completed boundary definition and performing meshing; Step S54: Making physical assumptions: The numerical simulation calculation is based on the following basic assumptions: assuming that the solid particles have the same diameter and that there is no agglomeration between the particles; ignoring the energy consumed by the solid particles during the collision and rebound process in the multi-stage rotary disk type continuous solid washing equipment; assuming that the components in the multi-stage rotary disk type continuous solid washing equipment will not be worn by the solid particles; Step S55: Setting the physical calculation model: Based on the software requirements used by the fluid calculation domain model, define the physical continuum for numerical simulation calculation and the physical calculation model used. The physical calculation model settings include: continuous phase turbulence model, Lagrangian phase discrete model, and material properties of the calculation medium; Step S56: Setting boundary condition values: setting boundary condition values ​​of the continuous phase and the discrete phase, respectively, according to actual process parameters; Step S57: Run numerical simulation calculation: Run numerical simulation calculation to obtain numerical simulation results of the performance of the multi-stage rotary disc type solid continuous washing equipment, and use them as subsequent evaluation parameters.

2. The numerical simulation and optimization analysis method of the multi-stage rotary disk type solid continuous washing equipment according to claim 1 is characterized in that: The structural parameters include the single-layer height, turntable paddle diameter, turntable paddle height, turntable diameter and annular partition opening diameter of the multi-stage turntable type solid continuous washing equipment; The process parameters include: material feeding speed, detergent feeding speed and turntable rotation speed of the multi-stage turntable type solid continuous washing equipment.

3. The numerical simulation and optimization analysis method of the multi-stage rotary disk type solid continuous washing equipment according to claim 1 is characterized in that: When performing the three-dimensional modeling operation on the equipment components in step S51, the set parameters include: the geometric shape and geometric size parameters of the turntable and the annular partition, and the positions and opening diameters of the material and detergent inlets and outlets.

4. The numerical simulation and optimization analysis method of the multi-stage rotary disk type solid continuous washing equipment according to claim 1 is characterized in that: In the step S53, the boundary condition type of the fluid calculation domain model is set as follows: the inlet boundary type is a mass flow inlet, and the outlet boundary type is an outlet with a specified mass flow; Meshing the fluid computational domain model includes: setting the mesh of the fluid computational domain to use a polyhedron unstructured mesh; performing local mesh encryption on the turntable wall, interface, annular partition, and baffle wall; and generating a prismatic boundary layer mesh on the surface of each wall.

5. The numerical simulation and optimization analysis method of the multi-stage rotary disk type solid continuous washing equipment according to claim 1 is characterized in that: In step S55, the setting of the physical calculation model specifically includes: Set the direction of gravity acceleration according to the placement of the multi-stage rotary disk type solid continuous washing equipment; The continuous phase turbulence model adopts the K-Epsilon two-layer model based on the Reynolds time-averaged method; The solver uses implicit unsteady solver and separated flow solver for transient solution, and the discretization format uses second-order upwind format; Create a continuous phase, Lagrangian phase, or discrete phase for each material based on actual industrial production, and set the material properties of each continuous phase separately, including density and dynamic viscosity; Create a Lagrangian phase, select a constant density material particle model, a residence time model, a two-way coupling model, and a turbulent dissipation model; Material properties of the discrete phase are set, the material properties including density.

6. The numerical simulation and optimization analysis method of the multi-stage rotary disk type solid continuous washing equipment according to claim 1 is characterized in that: In step S56, the numerical values ​​of each boundary condition of the continuous phase and the numerical values ​​of each boundary condition of the discrete phase are set according to the parameters designed in the orthogonal experimental factor level table, wherein the numerical values ​​of each boundary condition of the continuous phase include: mass flow rate, phase volume fraction; the numerical values ​​of each boundary condition of the discrete phase include: particle size, particle mass flow rate, particle flow velocity, and particle distribution mode.

7. The numerical simulation and optimization analysis method for the multi-stage rotary disk type continuous solid washing equipment according to claim 1, characterized in that: The step S57 includes: Step S571: Continuous phase simulation calculation: The Lagrangian phase solver is frozen, and the multi-stage rotary disk solid continuous washing equipment operates in a continuous phase state; the mass flow rate and phase volume fraction at each inlet and outlet section of the continuous phase are monitored. When the fluctuation of the monitored quantities does not exceed the preset fluctuation range and the fluctuation of the calculated residual is stable, it is determined that the continuous phase calculation has reached a stable state, and the process jumps to step S572; Step S572: discrete phase simulation calculation: enable the Lagrangian phase solver, and the discrete phase enters the multi-stage rotary disk type solid continuous washing equipment; monitor the average residence time of particles in the outlet area of ​​the multi-stage rotary disk type solid continuous washing equipment. When the fluctuation of the monitored amount does not exceed the preset fluctuation range and the calculated residual fluctuation is stable, it is determined that the discrete phase calculation has reached a stable state, the numerical simulation calculation is terminated, and the numerical simulation calculation results are obtained. The numerical simulation results include: the liquid phase impurity content at the material outlet, the average residence time of the particles, the stirring power density, and the solid retention in the tower.

8. The numerical simulation and optimization analysis method for the multi-stage rotary disk type solid continuous washing equipment according to claim 7, characterized in that: The calculation time step of the continuous phase simulation calculation is 0.1-0.5s; the calculation time step of the discrete phase simulation calculation is set according to a formula, and the formula makes the discrete phase particle movement conform to the particle movement distance within a single time step conform to a preset value.

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