Simulated liquid level dynamic control method based on Fluent continuous casting tundish

Abstract

The invention discloses a simulated liquid level dynamic control method based on a Fluent continuous casting tundish, which comprises the following steps: S1, establishing a geometric model of the tundish and a long nozzle, and carrying out grid division; s2, importing the geometric model of the tundish and the long nozzle subjected to grid division into Fluent software, and setting calculation parameters; s3, developing a Fluent user self-defined function, and importing the Fluent user self-defined function into Fluent compiling; and S4, after the user-defined function is imported into Fluent to be compiled, analog calculation is started, and dynamic control over the liquid steel level in the tundish is achieved. The method has the advantages that real-time dynamic control of the liquid level of the molten steel in the tundish in the simulation process is achieved, the liquid level is accurately controlled, the limitation of single-phase flow or constant flow assumption adopted in a traditional simulation method is overcome, the actual production working condition is met, and the consistency of the simulation result and the actual production process is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of numerical simulation of continuous casting in steel metallurgy, and in particular relates to a method for dynamic liquid level control in a continuous casting tundish simulation process based on Fluent. Background Art

[0002] In the continuous casting process, the tundish, a key metallurgical vessel connecting the ladle and the mold, fulfills crucial functions such as stabilizing the molten steel's composition and temperature, promoting the floating of inclusions, and evenly distributing the molten steel. Tundish level control is a key component in ensuring a stable continuous casting process, directly impacting key metallurgical parameters such as molten steel flow characteristics, temperature uniformity, and inclusion removal efficiency.

[0003] Numerical simulation technology plays an increasingly important role in tundish process optimization. Computational fluid dynamics (CFD) methods can accurately predict the flow behavior and temperature distribution of molten steel within the tundish. However, existing simulation methods have significant shortcomings in liquid level control: most studies use fixed liquid level or single-phase flow assumptions, which cannot truly reflect the process characteristics of dynamic liquid level adjustment via a sliding mechanism in actual production.

[0004] Chinese patent CN102402229A discloses a device and method for controlling the level of molten steel in a continuous casting tundish. While this technology provides a method for controlling the level of molten steel in the tundish, it does not involve numerical simulation of the casting process. Furthermore, Li Xin et al., in their paper "Physical and Numerical Simulation of Optimization of Four-Stream Tundish Structure," published in Continuous Casting, Vol. 44, No. 1, 2025, studied the flow behavior of a four-stream tundish through numerical simulation. While this study optimized the flow field of molten steel in the tundish, it did not address multiphase flow and level changes during the tundish casting process, which differs from the actual production process. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem that the liquid level control in the existing simulation process is inaccurate and cannot reflect the actual sliding nozzle adjustment process. It provides a dynamic control method for the simulated liquid level of the continuous casting ladle based on Fluent, which can realize real-time dynamic control of the molten steel level in the ladle during the simulation process, accurately control the liquid level, overcome the limitations of the traditional simulation method using single-phase flow or constant flow assumptions, conform to actual production conditions, significantly improve the consistency between the simulation results and the actual production process, and provide a liquid level control parameter optimization solution for actual production.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for dynamic liquid level control of continuous casting tundish simulation based on Fluent, the specific steps are as follows: S1, establish the geometric model of the tundish and shroud, and perform meshing; S2, import the meshed tundish and shroud geometry models into Fluent software and set calculation parameters; S3, develop Fluent user-defined functions and import them into Fluent for compilation; S4, after importing the above user-defined function into Fluent for compilation, starts simulation calculation to realize dynamic control of the steel liquid level in the tundish.

[0007] Furthermore, in step S1, a three-dimensional modeling software is used to establish a geometric model of the tundish including the shroud inlet and outlet.

[0008] Furthermore, in step S1, the geometric model is divided into structured grids, and grid encryption is performed in regions with complex structures.

[0009] Furthermore, in step S2, the Fluent software is opened, the tundish and shroud grid files are imported, and calculation parameters are set; wherein the calculation parameters include physical parameters, boundary conditions, solution method, initial liquid level, and calculation residual.

[0010] Furthermore, in step S2, the physical property parameters include molten steel density, air density, molten steel viscosity, and air viscosity.

[0011] Furthermore, in step S2, the boundary conditions are as follows: the shroud inlet is set to a user-defined function, the tundish outlet is set to a pressure outlet, the tundish top surface is set to a pressure outlet, the remaining walls are set to no-slip walls, the pressure-velocity coupling is set to the PISO format, the standard ke turbulence model and the VOF model are enabled, and the residual standard is set to be less than 1e-4.

[0012] Furthermore, in step S3, the required liquid level height is determined, and the position of the liquid level monitoring point is defined according to the height. The molten steel volume fraction point_SteelVOF at the monitoring point is obtained in real time through the C_VOF macro; and the molten steel flow rate Q_out at the outlet is obtained in real time through ReportDefinition.

[0013] Furthermore, in step S3, a liquid level-flow control equation is established: when the monitored liquid level molten steel volume fraction point_SteelVOF is lower than the set value, the inlet flow rate Q_in=(1+C)×Q_out; when the monitored liquid level molten steel volume fraction point_SteelVOF is higher than the set value, the inlet flow rate Q_in=(1-C)×Q_out; wherein C is the flow coefficient, which is used to control the liquid level change speed and is determined according to actual conditions.

[0014] Furthermore, in step S3, the liquid level-flow control equation is applied to the inlet boundary condition using the DEFINE_PROFILE macro.

[0015] In the technical solution of the present invention, a closed-loop control system for the ladle liquid level is established through the Fluent software platform combined with custom functions, and a liquid level-flow coupling calculation model is constructed to achieve real-time dynamic control of the molten steel level in the ladle during the simulation process. This can truly reflect the process of liquid level adjustment by the slide mechanism in actual production, overcoming the limitations of traditional simulation methods that adopt single-phase flow or constant flow assumptions. The dynamic control strategy of the present invention is more in line with actual production conditions, and the liquid level control accuracy deviation does not exceed 1%, which significantly improves the consistency between the simulation results and the actual production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of the method for dynamic liquid level control of the continuous casting tundish based on Fluent simulation of the present invention. DETAILED DESCRIPTION Example

[0017] To make the present invention more clear, the following further illustrates a method for dynamic control of the liquid level of a continuous casting tundish based on Fluent simulation in conjunction with the accompanying drawings. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] See also Figure 1 A Fluent-based method for dynamic liquid level control in a continuous casting tundish simulation process is presented. This method numerically simulates the process from casting start to liquid level stabilization in a tundish. Its characteristics are: (1) Use SolidWorks software to create the geometric model of the tundish and shroud; ICEM CFD was used to divide the structural mesh of the tundish and to perform local meshing on the flow stabilizer and liquid surface. (2) Import the generated mesh file into Fluent and set the calculation parameters; the calculation parameters include physical properties, boundary conditions, solution method, initial liquid level, and calculation residuals.

[0019] Among them, the physical parameters are: steel liquid density 7020 Kg / m 3 , air density 1.225 kg / m 3 , steel viscosity 0.006kg / m / s, air viscosity 1.7894e-05kg / m / s; Boundary conditions are: long water inlet is set as user-defined function, the middle package outlet is set as pressure outlet, the middle package top surface is set as pressure outlet, the rest wall surface is set as no slip wall surface, pressure-velocity coupling is set as PISO format, standard k-e turbulent flow model and VOF model are opened, residual standard is set as lower than 1e-4, initial liquid surface is set as 200 mm.

[0020] (Three) develop Fluent user-defined function and import Fluent compilation, in the embodiment, the liquid level is stable and the height is 800 mm, the liquid level monitoring point position coordinates are defined according to the height as (0, 0, 0.8), the steel volume fraction point_SteelVOF at the monitoring point is obtained by C_VOF macro real-time; Report Definition is set to obtain the steel flow Q_out at the outlet in real time; Establish liquid level-flow control equation: when the monitoring liquid level steel volume fraction point_SteelVOF is lower than the set value 0.5, the inlet flow Q_in=(1+C)×Q_out; when the monitoring liquid level steel volume fraction point_SteelVOF is higher than the set value, the inlet flow Q_in=(1-C)×Q_out; wherein, C is a flow coefficient, used to control the liquid level change speed, which is set to 0.2 in the embodiment; the liquid level-flow control equation is applied to the inlet boundary condition by using DEFINE_PROFILE macro; the user-defined function is imported into Fluent for compilation; (Four) start simulation calculation, the time step is set to 0.02 s during the calculation process, and a total of 600 s is calculated, the steel liquid flow field in the tundish from the beginning of pouring to the stable state of the liquid surface is simulated.

[0021] In the embodiment, the Fluent user-defined function is used to establish the steel liquid flow model in the tundish, which can accurately reflect the actual situation in the tundish pouring process, analyze the steel liquid flow behavior in the tundish, and provide guidance for the tundish metallurgical process.

[0022] In addition to the above embodiments, the present application can have other implementation manners. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present application.

Claims

1. A method for dynamic control of liquid level in a continuous casting tundish based on Fluent simulation, characterized by: S1, establish the geometric model of the tundish and shroud, and perform meshing; S2, import the meshed tundish and shroud geometry models into Fluent software and set calculation parameters; S3, develop Fluent user-defined functions and import them into Fluent for compilation; S4, after importing the above user-defined function into Fluent for compilation, starts simulation calculation to realize dynamic control of the steel liquid level in the tundish.

2. The method for dynamic control of liquid level in a continuous casting tundish based on Fluent according to claim 1, characterized in that: In step S1, a 3D modeling software is used to establish a geometric model of the tundish including the shroud inlet and outlet.

3. The method for dynamic control of liquid level in a continuous casting tundish based on Fluent according to claim 1, characterized in that: In the step S1, the geometric model is divided into structured grids, and grid encryption is performed in regions with complex structures.

4. The method for dynamic control of liquid level in a continuous casting tundish based on Fluent simulation according to any one of claims 1 to 3, characterized in that: In step S2, the Fluent software is opened, the tundish and shroud grid files are imported, and calculation parameters are set; wherein the calculation parameters include physical properties, boundary conditions, solution method, initial liquid level, and calculation residual.

5. The method for dynamic control of liquid level in a continuous casting tundish based on Fluent according to claim 4, characterized in that: In step S2, the physical property parameters include molten steel density, air density, molten steel viscosity, and air viscosity.

6. The method for dynamic control of liquid level in a continuous casting tundish based on Fluent according to claim 4, characterized in that: In step S2, the boundary conditions are as follows: the shroud inlet is set to a user-defined function, the tundish outlet is set to a pressure outlet, the tundish top surface is set to a pressure outlet, the remaining walls are set to no-slip walls, the pressure-velocity coupling is set to the PISO format, the standard Ke turbulence model and the VOF model are enabled, and the residual standard is set to be less than 1e-4.

7. The method for dynamic control of liquid level in continuous casting tundish based on Fluent simulation according to any one of claims 1 to 3, characterized in that: In step S3, the required liquid level height is determined, and the position of the liquid level monitoring point is defined according to the height. The molten steel volume fraction point_SteelVOF at the monitoring point is obtained in real time through the C_VOF macro; and the molten steel flow rate Q_out at the outlet is obtained in real time through Report Definition.

8. The method for dynamic control of liquid level in continuous casting tundish based on Fluent simulation according to any one of claims 1 to 3, characterized in that: In step S3, a liquid level-flow control equation is established: when the monitored liquid level molten steel volume fraction point_SteelVOF is lower than the set value, the inlet flow rate Q_in=(1+C)×Q_out; when the monitored liquid level molten steel volume fraction point_SteelVOF is higher than the set value, the inlet flow rate Q_in=(1-C)×Q_out; wherein C is the flow coefficient, which is used to control the liquid level change speed and is determined according to actual conditions.

9. The method for dynamic control of liquid level in continuous casting tundish based on Fluent simulation according to any one of claims 1 to 3, characterized in that: In step S3, the liquid level-flow control equation is applied to the inlet boundary condition using the DEFINE_PROFILE macro.

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