A method for early warning of slag runoff during ladle casting

Abstract

This invention provides an early warning method for slag runoff during steel ladle casting, comprising: 1) acquiring the structural and dimensional parameters of the steel ladle, establishing a three-dimensional model of the steel ladle, and performing mesh generation; 2) acquiring the casting speed, the initial liquid level of the molten steel in the ladle, and the trajectory of the sliding gate opening during casting under the given casting speed, and setting the dynamic mesh for the sliding gate using a dynamic layering method; 3) selecting the RNG k-ε turbulence model and the VOF model, and setting boundary conditions; 4) tracking the interface between the molten steel, slag, and air in the ladle; 5) obtaining slag runoff early warning conditions based on the tracking results and issuing a slag runoff early warning. This invention can realistically simulate the changing process of the sliding gate, improve the accuracy of model calculations, and significantly improve early warning efficiency.

Description

Technical Field

[0001] This invention belongs to the field of continuous steel casting simulation, specifically relating to an early warning method for slag runoff during ladle casting. Background Technology

[0002] Slag addition at the end of the continuous casting process is a significant cause of reduced steel cleanliness and deteriorated steel quality. The main components of ladle top slag are generally CaO-SiO2-Al2O3, with high oxidizing properties (FeO-MnO). Due to this high oxidizing property, slag addition from the ladle causes secondary oxidation of the molten steel in the tundish. Furthermore, after ladle slag enters the molten steel in the tundish, slag droplets also form inclusions, typically large in size. Some of these inclusions float to the tundish covering agent slag layer, while others flow with the molten steel in the tundish (especially in cases of short-circuit flow due to poor tundish design). These inclusions are easily captured by the initial shell of the continuously cast billet, adversely affecting the processing and service performance of the steel. For example, during rolling, they can easily cause surface defects in ultra-low carbon steel plates, reducing the fatigue resistance of bearing steel during service.

[0003] Scholars have discovered three slag discharge mechanisms at the end of the continuous casting process: confluence vortices, discharge pits, and slag-steel emulsification. Confluence vortex slag discharge occurs at the end of the unsteady casting process in the continuous casting ladle. When the molten steel in the ladle drops to a certain height, a vortex forms above the nozzle. Molten slag is drawn into the molten steel through the vortex core. As casting continues, the vortex eventually penetrates the nozzle and enters the tundish, causing a large amount of slag discharge. Confluence vortices occur relatively early, when the ladle level is higher. The formation and eventual transition of the confluence vortex into a discharge pit strongly promotes slag-steel emulsification, causing the molten slag to be more diffusely distributed into the molten steel as it enters the tundish. Therefore, slag discharge caused by confluence vortices is the most harmful and the primary cause of slag discharge from the ladle.

[0004] Research on the mechanism of slag runoff from vortex flow in steel ladles and its influencing factors has primarily relied on physical and numerical simulations by scholars both domestically and internationally. The critical slag runoff height (the height of the liquid level when a vortex forms on the fluid surface) is generally used to evaluate the degree of slag runoff from the ladle. Furthermore, the critical slag runoff height is also a crucial parameter in actual production processes and a necessary prerequisite for developing slag runoff control technology. Current studies on slag runoff from vortex flow in steel ladles and the critical slag runoff height typically use direct-flow casting (100% slide gate opening) or ball valve control (as used in physical simulations) to set the ladle nozzle opening. However, in continuous casting production, the slide gate opening of the ladle nozzle dynamically changes to stabilize the tundish level and match the casting speed. Therefore, how to objectively and accurately reflect the actual dynamic changes during ladle casting and improve the predictability of slag runoff from vortex flow remains a problem that needs to be solved. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an early warning method for vortex slag falling during the ladle casting process. The method aims to quickly and objectively reflect the changes in molten steel and slag during the actual casting process, improve the prediction accuracy of vortex slag falling, and provide effective data support for slag falling early warning.

[0006] Based on the purpose of this invention, a method for early warning of slag runoff during ladle casting is provided, comprising:

[0007] 1) Obtain the structural and dimensional parameters of the ladle, establish a three-dimensional model of the ladle and perform mesh generation. The structure of the ladle includes the ladle body, the upper water inlet, the sliding water inlet and the lower water inlet located at the bottom of the ladle. The interfaces of the upper water inlet, the sliding water inlet and the lower water inlet in the three-dimensional model of the ladle are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition.

[0008] 2) Obtain the casting speed of the ladle, the initial liquid level of the molten steel in the ladle, and the trajectory of the sliding gate opening during the casting process under the casting speed condition. Use the dynamic layup method to set the dynamic mesh of the sliding gate.

[0009] 3) Select the RNG k-ε turbulence model and the VOF model, set the upper opening of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity and hydraulic diameter at the pressure inlet, and the turbulence intensity and hydraulic diameter at the pressure outlet.

[0010] 4) Track the interface between molten steel, slag and air in the ladle according to the model in step 3), wherein the sum of the volume fractions of molten steel, slag and air is controlled to be 1.

[0011] 5) Based on the tracking results of step 4), obtain the slag discharge warning conditions and issue a slag discharge warning.

[0012] Furthermore, in step 1), the ladle and the sliding gate slide body are divided into a hexahedral grid, and the top and bottom of the ladle and the bottom of the sliding gate slide are divided into an O-shaped grid.

[0013] Furthermore, in step 2), the DEFINE_CG_MOTION macro in the UDF is used to define the skateboard mesh motion in FLUENT according to the relationship between the obtained sliding gate opening and time.

[0014] Furthermore, in step 3), the turbulence intensity at the pressure inlet... Among them, the Reynolds number at the pressure inlet In the formula, Fluid density, kg / m³ 3 ; The hydraulic diameter at the pressure inlet is in mm; ρ is the kinematic viscosity of the fluid, Pa·s; ρ is the average fluid velocity at the pressure inlet. In the formula, and These represent the cross-sectional areas at the pressure inlet and pressure outlet, respectively, and the average fluid velocity at the pressure outlet. In the formula, g is the acceleration due to gravity, 9.8 m / s². 2 H represents the initial liquid level of molten steel in the ladle, in mm; turbulence intensity at the pressure outlet. Among them, the Reynolds number at the pressure outlet In the formula, The hydraulic diameter at the pressure outlet is in mm (i.e., the outlet diameter of the drain).

[0015] Furthermore, in step 4), the tracking specifically adopts the pressure-velocity coupled implicit (PISO) algorithm of Fluent software, and uses the Courant number to control the time step. The initial minimum time step is 0.001s, and the Courant number is 0.5~1, until the casting is completed.

[0016] Furthermore, in step 5), the slag discharge warning condition is the generation of a vortex at the interface between the steel and slag.

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

[0018] The present invention employs a dynamic layering method to set up a dynamic mesh for the sliding gate, which can more realistically simulate the change process of the sliding gate. On this basis, the RNG k-ε turbulence model and VOF model are used and appropriate boundary conditions are selected to further improve the accuracy of model calculation. At the same time, compared with traditional water simulation experiments, the early warning efficiency is greatly improved. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a steel ladle modeling according to an embodiment of the present invention;

[0020] Figure 2 This is a diagram showing the change in the opening degree of the sliding gate slide plate in Embodiment 1 of the present invention;

[0021] Figure 3 This is a cloud map showing the changes in the steel slag interface during slag discharge warning in Embodiment 1 of the present invention;

[0022] Figure 4 This is a diagram of the critical state of slag loading obtained from the water simulation experiment in Embodiment 1 of the present invention;

[0023] Figure 5This is a diagram showing the change in the opening degree of the sliding gate slide plate in Embodiment 2 of the present invention;

[0024] Figure 6 This is a diagram showing the change in the opening degree of the sliding gate slide plate in Embodiment 3 of the present invention;

[0025] Figure 7 This is a diagram showing the change in the opening degree of the sliding gate slide plate in Embodiment 4 of the present invention. Detailed Implementation

[0026] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The ladle size parameters used in the specific embodiments of the present invention are shown in Table 1. The first-class continuous casting machine has a casting cross-section of 1255mm×230mm. The steel throughput is determined based on the cross-section size and the actual production casting speed.

[0028] Table 1 Dimensional parameters of steel ladle

[0029]

[0030] Example 1

[0031] A method for early warning of slag runoff during ladle casting includes:

[0032] 1) Obtain the structural and dimensional parameters of the ladle, establish a 3D model of the ladle, and perform mesh generation, such as... Figure 1 As shown, the structure of the ladle includes the ladle body, an upper water inlet, a sliding water inlet, and a lower water inlet located at the bottom of the ladle. In the three-dimensional model of the ladle, the interfaces of the upper water inlet, the sliding water inlet, and the lower water inlet are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition.

[0033] 2) Obtain the casting speed V during the ladle casting process. casting =1.46m / min, the relationship between the sliding gate opening and time under this pulling speed condition is shown in [reference]. Figure 2 The dynamic layering method is used to set the dynamic mesh of the sliding gate. The DEFINE_CG_MOTION macro in UDF is used to define the sliding gate mesh motion in FLUENT according to the relationship between the sliding gate opening and time.

[0034] 3) Select the RNG k-ε turbulence model and the VOF model, set the upper inlet of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity at the pressure inlet. and hydraulic diameter Turbulence intensity at the pressure outlet and hydraulic diameter ; Turbulence intensity at the pressure inlet Among them, the Reynolds number at the pressure inlet In the formula, The fluid density is 7020 kg / m³. 3 ; The hydraulic diameter at the pressure inlet is 3140 mm. The dynamic viscosity of the fluid is 0.0055 Pa·s; the average fluid velocity at the pressure inlet is... In the formula, and These represent the cross-sectional areas at the pressure inlet and pressure outlet, respectively. 7.74m respectively 2 and 3.52×10 -3 m 2 Average fluid velocity at the pressure outlet In the formula, g is the acceleration due to gravity, 9.8 m / s². 2 H represents the initial liquid level of molten steel in the ladle, in mm; turbulence intensity at the pressure outlet. Among them, the Reynolds number at the pressure outlet In the formula, The hydraulic diameter at the pressure outlet is 67 mm.

[0035] 4) The pressure-velocity coupling implicit algorithm (PISO algorithm) in Fluent software is used to track the interface between molten steel, slag and air in the ladle. The sum of the volume fractions of molten steel, slag and air is controlled to be 1. The time step is controlled by the Coulomb number with an initial minimum time step of 0.001s and the Coulomb number of 0.5 until the casting is completed. The change cloud map of the steel-slag interface is obtained based on the tracking results. According to the obtained change cloud map, when the liquid level drops to a certain height, the molten steel surface layer at the steel-slag interface above the nozzle first shows a depression and begins to develop. At the same time, the free liquid surface begins to change. As the molten steel around the ladle continuously flows towards the center of the nozzle, the velocity gradient accumulation of the molten steel fluid layer near the outlet is aggravated. After a certain degree, it will drive the fluid of the adjacent upper layer to undergo the same evolution. This is transmitted layer by layer to the interface between the molten steel surface and the slag layer, causing the interface to gradually become unstable.

[0036] 5) When the tracking result of step 4) shows that the interface between the molten steel surface and the slag layer becomes unstable, a slag-fall warning is issued. The critical time at this time is 2442s, and the critical height of slag falling from the molten steel surface is 137mm.

[0037] During the actual pouring process, slag formation occurred at a pouring time of 2460 seconds, corresponding to a molten steel level of 133 mm. Therefore, the prediction method in this embodiment has an error of only 2.92%.

[0038] Example 2

[0039] A method for early warning of slag runoff during ladle casting includes:

[0040] 1) Obtain the structural and dimensional parameters of the ladle, establish a 3D model of the ladle, and perform mesh generation, such as... Figure 1 As shown, the structure of the ladle includes the ladle body, an upper water inlet, a sliding water inlet, and a lower water inlet located at the bottom of the ladle. In the three-dimensional model of the ladle, the interfaces of the upper water inlet, the sliding water inlet, and the lower water inlet are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition.

[0041] 2) Obtain the casting speed V during the ladle casting process. casting =1.3m / min, the relationship between the sliding gate opening and time under this pulling speed condition is shown in [reference]. Figure 3 The dynamic layering method is used to set the dynamic mesh of the sliding gate. The DEFINE_CG_MOTION macro in UDF is used to define the sliding gate mesh motion in FLUENT according to the relationship between the sliding gate opening and time.

[0042] 3) Select the RNG k-ε turbulence model and the VOF model, set the upper inlet of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity at the pressure inlet. and hydraulic diameter Turbulence intensity at the pressure outlet and hydraulic diameter ; Turbulence intensity at the pressure inlet Among them, the Reynolds number at the pressure inlet In the formula, Fluid density, kg / m³ 3 ; The hydraulic diameter at the pressure inlet is 3140 mm. The fluid's kinematic viscosity is 0.0055 Pa·s; the average fluid velocity at the pressure inlet is... In the formula, and These represent the cross-sectional areas at the pressure inlet and pressure outlet, respectively, and the average fluid velocity at the pressure outlet. In the formula, g is the acceleration due to gravity, 9.8 m / s². 2 H represents the initial liquid level of molten steel in the ladle, in mm; turbulence intensity at the pressure outlet. Among them, the Reynolds number at the pressure outlet In the formula, The hydraulic diameter at the pressure outlet is 67 mm.

[0043] 4) The VOF model in Fluent software was used to simulate the ladle casting process. The pressure-velocity coupled implicit algorithm (PISO algorithm) was used to track the interface between molten steel, slag and air in the ladle. The sum of the volume fractions of molten steel, slag and air was controlled to be 1. The time step was controlled by the Coulomb number with an initial minimum time step of 0.001s and the Coulomb number of 1 until the casting was completed. The change cloud map of the steel-slag interface was obtained based on the tracking results. According to the obtained change cloud map, when the liquid level drops to a certain height, the molten steel surface layer at the steel-slag interface above the nozzle first shows a depression and begins to develop. At the same time, the free liquid surface begins to change. As the molten steel around the ladle continuously flows towards the center of the nozzle, the velocity gradient accumulation of the molten steel fluid layer near the outlet is aggravated. After a certain degree, it will drive the fluid of the adjacent upper layer to undergo the same evolution. This is transmitted layer by layer to the interface between the molten steel surface and the slag layer, causing the interface to gradually become unstable.

[0044] 5) When the tracking result of step 4) shows that the interface between the molten steel surface and the slag layer becomes unstable, a slag-fall warning is issued. The critical time at this time is 2702s, and the critical height of slag falling from the molten steel surface is 125mm.

[0045] During the actual pouring process, slag formation occurred at a pouring time of 2710 seconds, corresponding to a molten steel level of 121 mm. Therefore, the prediction method in this embodiment has an error of only 3.2%.

[0046] Example 3

[0047] A method for early warning of slag runoff during ladle casting includes:

[0048] 1) Obtain the structural and dimensional parameters of the ladle, establish a 3D model of the ladle, and perform mesh generation, such as... Figure 1 As shown, the structure of the ladle includes the ladle body, an upper water inlet, a sliding water inlet, and a lower water inlet located at the bottom of the ladle. In the three-dimensional model of the ladle, the interfaces of the upper water inlet, the sliding water inlet, and the lower water inlet are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition.

[0049] 2) Obtain the casting speed V during the ladle casting process.casting =1.1m / min, the relationship between the sliding gate opening and time under this pulling speed condition is shown in [reference]. Figure 4 The dynamic layering method is used to set the dynamic mesh of the sliding gate. The DEFINE_CG_MOTION macro in UDF is used to define the sliding gate mesh motion in FLUENT according to the relationship between the sliding gate opening and time.

[0050] 3) Select the RNG k-ε turbulence model and the VOF model, set the upper inlet of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity at the pressure inlet. and hydraulic diameter Turbulence intensity at the pressure outlet and hydraulic diameter ; Turbulence intensity at the pressure inlet Among them, the Reynolds number at the pressure inlet In the formula, Fluid density, kg / m³ 3 ; The hydraulic diameter at the pressure inlet is 3140 mm. The fluid's kinematic viscosity is 0.0055 Pa·s; the average fluid velocity at the pressure inlet is... In the formula, and These represent the cross-sectional areas at the pressure inlet and pressure outlet, respectively, and the average fluid velocity at the pressure outlet. In the formula, g is the acceleration due to gravity, 9.8 m / s². 2 H represents the initial liquid level of molten steel in the ladle, in mm; turbulence intensity at the pressure outlet. Among them, the Reynolds number at the pressure outlet In the formula, The hydraulic diameter at the pressure outlet is 67 mm.

[0051] 4) The VOF model in Fluent software was used to simulate the ladle casting process. The pressure-velocity coupled implicit algorithm (PISO algorithm) was used to track the interface between molten steel, slag and air in the ladle. The sum of the volume fractions of molten steel, slag and air was controlled to be 1. The time step was controlled by the Coulomb number with an initial minimum time step of 0.001s and the Coulomb number of 1 until the casting was completed. The change cloud map of the steel-slag interface was obtained based on the tracking results. According to the obtained change cloud map, when the liquid level drops to a certain height, the molten steel surface layer at the steel-slag interface above the nozzle first shows a depression and begins to develop. At the same time, the free liquid surface begins to change. As the molten steel around the ladle continuously flows towards the center of the nozzle, the velocity gradient accumulation of the molten steel fluid layer near the outlet is aggravated. After a certain degree, it will drive the fluid of the adjacent upper layer to undergo the same evolution. This is transmitted layer by layer to the interface between the molten steel surface and the slag layer, causing the interface to gradually become unstable.

[0052] 5) When the tracking result of step 4) shows that the interface between the molten steel surface and the slag layer becomes unstable, a slag-fall warning is issued. The critical time at this time is 3124s, and the critical height of slag falling from the molten steel surface is 118mm.

[0053] During the actual pouring process, slag formation occurred at a pouring time of 3130 seconds, corresponding to a molten steel level of 115 mm. Therefore, the prediction method in this embodiment has an error of only 2.54%.

[0054] Example 4

[0055] A method for early warning of slag runoff during ladle casting includes:

[0056] 1) Obtain the structural and dimensional parameters of the ladle, establish a 3D model of the ladle, and perform mesh generation, such as... Figure 1 As shown, the structure of the ladle includes the ladle body, an upper water inlet, a sliding water inlet, and a lower water inlet located at the bottom of the ladle. In the three-dimensional model of the ladle, the interfaces of the upper water inlet, the sliding water inlet, and the lower water inlet are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition.

[0057] 2) Obtain the casting speed V during the ladle casting process. casting = 0.9 m / min, the relationship between the sliding gate opening and time under this pulling speed condition is shown in [reference]. Figure 5 The dynamic layering method is used to set the dynamic mesh of the sliding gate. The DEFINE_CG_MOTION macro in UDF is used to define the sliding gate mesh motion in FLUENT according to the relationship between the sliding gate opening and time.

[0058] 3) Select the RNG k-ε turbulence model and the VOF model, set the upper inlet of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity at the pressure inlet. and hydraulic diameter Turbulence intensity at the pressure outlet and hydraulic diameter ; Turbulence intensity at the pressure inlet Among them, the Reynolds number at the pressure inlet In the formula, Fluid density, kg / m³ 3 ; The hydraulic diameter at the pressure inlet is 3140 mm. The fluid's kinematic viscosity is 0.0055 Pa·s; the average fluid velocity at the pressure inlet is... In the formula, and These represent the cross-sectional areas at the pressure inlet and pressure outlet, respectively, and the average fluid velocity at the pressure outlet. In the formula, g is the acceleration due to gravity, 9.8 m / s². 2 H represents the initial liquid level of molten steel in the ladle, in meters; turbulence intensity at the pressure outlet. Among them, the Reynolds number at the pressure outlet In the formula, The hydraulic diameter at the pressure outlet is 67 mm.

[0059] 4) The VOF model in Fluent software was used to simulate the ladle casting process. The pressure-velocity coupled implicit algorithm (PISO algorithm) was used to track the interface between molten steel, slag and air in the ladle. The sum of the volume fractions of molten steel, slag and air was controlled to be 1. The time step was controlled by the Coulomb number with an initial minimum time step of 0.001s and the Coulomb number of 1 until the casting was completed. The change cloud map of the steel-slag interface was obtained based on the tracking results. According to the obtained change cloud map, when the liquid level drops to a certain height, the molten steel surface layer at the steel-slag interface above the nozzle first shows a depression and begins to develop. At the same time, the free liquid surface begins to change. As the molten steel around the ladle continuously flows towards the center of the nozzle, the velocity gradient accumulation of the molten steel fluid layer near the outlet is aggravated. After a certain degree, it will drive the fluid of the adjacent upper layer to undergo the same evolution. This is transmitted layer by layer to the interface between the molten steel surface and the slag layer, causing the interface to gradually become unstable.

[0060] 5) When the tracking result of step 4) shows that the interface between the molten steel surface and the slag layer becomes unstable, a slag-fall warning is issued. The critical time at this time is 3739s and the critical height of slag falling from the molten steel surface is 97mm.

[0061] During the actual pouring process, slag formation occurred at a pouring time of 3750 seconds, corresponding to a molten steel surface height of 94 mm. Therefore, the prediction method in this embodiment has an error of only 3.09%.

[0062] It should be noted that, based on the above embodiments of the present invention, those skilled in the art can fully realize the scope of the independent claims and dependent claims of the present invention, and the implementation process and methods are the same as those in the above embodiments; and the parts of the present invention not described in detail belong to the well-known technology in the art. However, the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A method for early warning of slag runoff during ladle casting, characterized in that, Includes the following steps: 1) Obtain the structural and dimensional parameters of the ladle, establish a three-dimensional model of the ladle and perform mesh generation. The structure of the ladle includes the ladle body, the upper water inlet, the sliding water inlet and the lower water inlet located at the bottom of the ladle. The interfaces of the upper water inlet, the sliding water inlet and the lower water inlet in the three-dimensional model of the ladle are connected by a fluid interface, and the wall surface is set as a no-slip wall boundary condition. 2) Obtain the casting speed of the ladle, the initial liquid level of the molten steel in the ladle, and the trajectory of the sliding gate opening change during the casting process under the casting speed condition. Use the dynamic layup method to set the dynamic mesh of the sliding gate. Use the DEFINE_CG_MOTION macro in UDF to define the sliding gate mesh motion in FLUENT according to the obtained sliding gate opening and time relationship. 3) Select the RNG k-ε turbulence model and the VOF model, set the upper opening of the ladle as the pressure inlet boundary, the inlet material as air, and the inlet pressure as standard atmospheric pressure, set the lower outlet as the pressure outlet boundary, and the outlet pressure as standard atmospheric pressure, and set the interface as a no-slip boundary condition; set the turbulence intensity and hydraulic diameter at the pressure inlet, and the turbulence intensity and hydraulic diameter at the pressure outlet. 4) Track the interface between molten steel, slag and air in the ladle according to the model in step 3), wherein the sum of the volume fractions of molten steel, slag and air is controlled to be 1. 5) Based on the tracking results of step 4), obtain the slag discharge warning conditions and issue a slag discharge warning.

2. The early warning method as described in claim 1, characterized in that, In step 1), the ladle and nozzle body are divided into grids using a structural hexahedral grid, while the top and bottom of the ladle and the bottom of the nozzle are divided into O-type grids.

3. The early warning method as described in claim 1 or 2, characterized in that, In step 4), the tracking specifically adopts a pressure-velocity coupled implicit algorithm, using the Courant number to control the time step, with an initial minimum time step of 0.001s, until the pouring is completed.

4. The early warning method as described in claim 3, characterized in that, The Courant number is 0.5 to 1.

5. The early warning method as described in claim 4, characterized in that, In step 5), the slag discharge warning condition is the generation of a vortex at the interface between the steel and slag.

Images