A method for simulating ladle pouring and slag removal using water simulation experiment

Abstract

An embodiment of the present invention provides a method for simulating ladle pouring slag discharge using a water simulation experiment. The method comprises obtaining a sliding nozzle opening control curve using a water simulation experiment model; simulating the ladle pouring process using the water simulation experiment model and the sliding nozzle opening control curve; and determining ladle pouring slag discharge parameters during the simulated ladle pouring process, wherein the slag discharge parameters include a critical slag discharge height, a slag discharge vortex diameter, and a slag discharge time. This scheme allows the sliding nozzle opening in the water simulation experiment to be consistent with actual production conditions, thereby obtaining accurate parameters for ladle slag discharge, and further enabling the development of measures to control vortex generation and improve the quality of finished products.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical automation, in particular to a method for simulating ladle pouring and slag removal by using a water simulation experiment. Background Art

[0002] The factors affecting the cleanliness of molten steel involve all aspects of molten steel smelting and continuous casting. Among them, slag discharge at the end of ladle pouring during continuous casting is an important reason for reducing the cleanliness of molten steel and deteriorating steel quality.

[0003] Research has revealed three mechanisms for ladle slagging at the end of ladle pouring: converging vortices, drainage pits, and slag-steel emulsification. Converging vortices are the primary cause of ladle slagging. Converging vortices occur at the end of the unsteady-state pouring phase of a continuous casting ladle. When the molten steel drops to a certain height, a vortex forms above the nozzle. Slag is drawn into the molten steel through the vortex core. As pouring progresses, the vortex eventually penetrates the nozzle and enters the tundish, causing significant slagging. After ladle slagging, the slag forms inclusions in the tundish. While some of these inclusions rise due to buoyancy and are absorbed by the tundish coating, a portion of them continues to flow with the molten steel in the tundish, through the submerged nozzle, and into the mold. These inclusions are easily captured by the primary shell of the continuous casting billet, causing surface defects in ultra-low carbon steel during subsequent rolling. This can also reduce the fatigue performance of steel grades with critical fatigue life requirements. Therefore, in order to suppress the vortex slag at the end of ladle pouring, ensure the cleanliness of molten steel and improve the quality of steel, it is very necessary to conduct in-depth research on the vortex slag.

[0004] Currently, most domestic and international researchers have studied the mechanisms and influencing factors of slag discharge caused by the converging vortex at the end of ladle casting through water simulation experiments. These models mimic actual continuous casting equipment at a specific scale, using water instead of molten steel and following a process flow identical to the actual production process to maximize the reproduction of the actual production process and obtain the desired research results. Therefore, current technology generally uses water simulation experiments to simulate the converging vortex during the casting process to obtain relevant parameters for ladle slag discharge, thereby enabling measures to be taken in actual production to prevent slag from entering the crystallizer and improve steel quality.

[0005] In the process of implementing the present invention, the inventors discovered that the prior art has at least the following problems:

[0006] In the water simulation experiments of the prior art, the setting of the sliding nozzle opening of the ladle in the water simulation is always controlled by straight-through pouring (i.e., the sliding plate opening is 100%) or ball valve. However, in the actual pouring process of the continuous casting ladle, in order to coordinate the pulling speed and stabilize the molten steel level in the intermediate ladle, the staff needs to adjust the opening of the sliding nozzle according to the molten steel level in the intermediate ladle, so the opening of the sliding nozzle is dynamically changing. That is, the existing technology cannot simulate the slag discharge process at the end of the actual pouring of the ladle, and cannot reflect the actual state of the ladle pouring, resulting in the inability to accurately and quantitatively analyze key parameters such as the critical height of the vortex and the surface vortex diameter. Therefore, how to make the opening of the sliding nozzle in the water simulation experiment consistent with the actual production situation, so as to obtain accurate parameters for the slag discharge of the ladle, and then be able to propose measures to control the generation of vortices, is a problem that needs to be solved. Summary of the Invention

[0007] The embodiment of the present invention provides a method for simulating ladle pouring and slag discharge by using a water simulation experiment, so as to solve the problem that the ladle slag discharge parameters obtained in the water simulation experiment in the prior art are not accurate enough.

[0008] To achieve the above-mentioned purpose, an embodiment of the present invention provides a method for simulating slag discharge in ladle pouring using a water simulation experiment, comprising: obtaining a sliding gate opening control curve through a water simulation experiment model; simulating the ladle pouring process through the water simulation experiment model and the sliding gate opening control curve; in the simulated ladle pouring process, determining the slag discharge parameters of the ladle pouring, the slag discharge parameters including the critical slag discharge height, the slag discharge vortex diameter and the slag discharge time.

[0009] Furthermore, a sliding gate opening control curve is obtained through a water simulation experimental model, specifically including: adding water into the ladle model to the initial liquid level height of the ladle model; fully opening the sliding gate at the bottom of the ladle model to allow the water in the ladle model to be injected into the tundish model; when the liquid level in the tundish model reaches the expected liquid level height of the tundish, dynamically adjusting the opening of the sliding gate so that the difference between the liquid level in the tundish model and the expected liquid level height of the tundish model is maintained within a preset variation range; the time when the liquid level in the tundish model reaches the expected liquid level height of the tundish is used as the first set time; and drawing the sliding gate opening control curve based on the data of the change in the opening of the sliding gate over time.

[0010] Furthermore, the ladle pouring process is simulated by using a water simulation experimental model and a sliding gate opening control curve, specifically including: setting a sliding gate adjustment device on the water simulation experimental model; adding water to the ladle model to the initial liquid level height of the ladle model; fully opening the sliding gate through the sliding gate adjustment device; after reaching the first set time, making the sliding gate adjustment device perform real-time adjustment of the sliding gate opening according to the sliding gate opening control curve until all the water in the intermediate ladle model is discharged.

[0011] Furthermore, in the simulated ladle pouring process, the slag discharge parameters of the ladle pouring are determined, specifically including: observing whether a vortex appears on the liquid surface in the ladle model; if a vortex appears on the liquid surface in the ladle model, measuring the liquid surface height and the vortex diameter when the vortex appears in the ladle model by a ruler, and recording the time consumed from the start of the simulated ladle pouring process to the appearance of the vortex; using the measured liquid surface height as the critical slag discharge height, the measured vortex diameter as the slag discharge vortex diameter, and the recorded time as the slag discharge time.

[0012] Furthermore, before obtaining the sliding gate opening control curve through the water simulation experiment model, the method further includes: constructing a water simulation experiment model, the water simulation experiment model including a ladle model and a tundish model.

[0013] Furthermore, before obtaining the sliding gate opening control curve through the water simulation experimental model, it also includes: obtaining the liquid level control parameters of the simulated ladle pouring, the liquid level control parameters including the initial liquid level height of the ladle model and the expected liquid level height of the tundish model.

[0014] Furthermore, a water simulation experimental model is constructed, specifically including: measuring the actual ladle size and the actual tundish size; converting the actual ladle size and the actual tundish size into the ladle model size and the tundish model size respectively according to a preset ratio; and constructing a water simulation experimental model according to the ladle model size and the tundish model size.

[0015] Furthermore, the liquid level control parameters of the simulated ladle pouring are obtained, specifically including: obtaining the initial liquid level height of the actual ladle and the expected liquid level height of the actual tundish through the actual ladle pouring test; according to the preset ratio, the initial liquid level height of the actual ladle and the expected liquid level height of the actual tundish are converted into the initial liquid level height of the ladle model and the expected liquid level height of the tundish model respectively.

[0016] Furthermore, the sliding gate adjustment device is provided on the water simulation test model, specifically comprising: using a servo motor, an electric cylinder and a connecting rod to construct the sliding gate adjustment device.

[0017] Furthermore, in the process of dynamically adjusting the opening of the sliding gate to keep the difference between the liquid level in the tundish model and the expected liquid level height of the tundish within a preset variation range, a dichotomy method is used to determine the adjustment value of the sliding gate.

[0018] The above technical solution has the following beneficial effects:

[0019] The technical solution of the present invention provides a basis for controlling the sliding nozzle opening in actual simulation experiments by generating a control curve for reflecting the relationship between the sliding nozzle opening and time. At the same time, combined with the unique water model automatic flow control system, it can more accurately simulate the actual pouring process, maintain the stability of the ladle liquid level during the simulation process, and truly simulate the vortex slag situation in the actual production process, so as to find the key parameters for controlling the slag under the vortex and obtain a more realistic critical height and diameter of the vortex; at the same time, compared with the existing technology, the flow control pouring time is closer to the theoretical simulation time, and is more conducive to accurately simulating the on-site pouring process. These outstanding features are all conducive to providing accurate control parameters for actual production, proposing measures to control the generation of vortices, and avoiding the influence of steel slag on finished steel products during the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a flow chart of a method for simulating ladle pouring and slag removal using a water simulation experiment according to an embodiment of the present invention;

[0022] Figure 2 Schematic diagram of liquid level changes of a ladle model and a tundish model during a non-steady-state pouring process in a specific embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the change of the sliding gate opening during the non-steady-state pouring process in a specific example of the present invention;

[0024] Figure 4 This is a comprehensive schematic diagram of the changes in the sliding gate opening, the ladle model liquid level, and the tundish model liquid level during the steady-state pouring process in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions 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 making any creative efforts are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a method for simulating ladle pouring and slag removal using a water simulation experiment, comprising:

[0027] S100, obtaining a sliding gate opening control curve through a water simulation experimental model;

[0028] S200, simulating the ladle pouring process using a water simulation experimental model and the sliding gate opening control curve;

[0029] S300. During the simulated ladle pouring process, determining slag discharging parameters for ladle pouring, wherein the slag discharging parameters include a critical slag discharging height, a slag discharging vortex diameter, and a slag discharging time.

[0030] In order to solve the problem of inaccurate simulation of the slag discharge process in the aforementioned water simulation experiment, the present invention first obtains the required sliding gate opening control curve through preliminary experiments before the simulation. At a specific stage of the experimental process, the sliding gate opening is continuously adjusted to maintain the liquid level in the ladle stable, so as to obtain the opening value of the sliding gate at each moment, and the opening values ​​at all moments are connected into a curve, and then the sliding gate opening can be automatically adjusted by designing an automatic sliding plate adjustment device. In the actual simulation process, the sliding gate opening is adjusted in real time according to the aforementioned control curve by the automatic adjustment device to achieve flow control casting, and the experimental results obtained can truly reflect the vortex slag situation in the production process. On this basis, the vortex formation process during the casting process is observed, and the influence of different factors on vortex formation is systematically studied, and measures to control the generation of vortices are proposed.

[0031] Furthermore, the step S100 specifically includes:

[0032] S110, adding water to the ladle model to an initial liquid level of the ladle model;

[0033] S120, fully opening the sliding gate at the bottom of the ladle model to allow water in the ladle model to flow into the tundish model;

[0034] S130, when the liquid level in the tundish model reaches the expected liquid level height of the tundish, dynamically adjusting the opening of the slide gate so that the difference between the liquid level in the tundish model and the expected liquid level height of the tundish model is maintained within a preset variation range;

[0035] S140, setting the time when the liquid level in the tundish model reaches the expected liquid level height of the tundish as a first set time;

[0036] S150 , drawing the sliding gate opening control curve according to the data of the sliding gate opening changing with time.

[0037] According to the similarity principle of the water model experiment, the water model experiment simulates the changes in the liquid level of the ladle and the tundish during the ladle pouring process, which is divided into two stages: non-steady-state pouring (also known as tundish filling) and steady-state pouring. During non-steady-state pouring, that is, the sliding gate opening of the ladle model is 100%, and the liquid level of the tundish continues to rise; when the tundish liquid level rises to a certain value (that is, the expected liquid level height of the tundish), according to production requirements, the liquid level of the tundish needs to be kept stable. If the sliding gate opening is still fully open, the subsequent tundish liquid level will continue to rise and cannot be maintained within the stable range. Therefore, dynamic adjustment of the sliding gate opening is required. In summary, in the preliminary experiment, there is no need to adjust the sliding gate opening during the non-steady-state pouring process. This stage does not need to be studied. It is only necessary to obtain the curve of the sliding gate opening value changing with time during the steady-state pouring process.

[0038] Furthermore, the step S200 specifically includes:

[0039] S210, installing a sliding gate adjustment device on the water simulation test model;

[0040] S220, adding water to the ladle model to an initial liquid level of the ladle model;

[0041] S230, fully opening the sliding gate through the sliding gate adjusting device;

[0042] S240. After the first set time is reached, the sliding gate adjustment device is enabled to adjust the sliding gate opening in real time according to the sliding gate opening control curve until all the water in the tundish model is discharged.

[0043] After obtaining the sliding gate opening control curve, the curve can be used to automatically control the simulated pouring during the pouring simulation. To this end, all data values ​​in the entire sliding gate opening control curve can be imported into relevant software to generate an automatic control script. When this script is run during the simulation, the sliding gate opening can be automatically controlled, thereby achieving a water model experiment for ladle pouring that is identical to the sliding gate variation process in actual production, ensuring a stable tundish liquid level during the simulation and obtaining authentic and reliable data.

[0044] Furthermore, the step S300 specifically includes:

[0045] S310, observing whether a vortex appears on the liquid surface in the ladle model;

[0046] S320, if a vortex appears on the liquid surface in the ladle model, measuring the liquid surface height and the vortex diameter when the vortex appears in the ladle model using a ruler, and recording the time taken from the start of the simulated ladle pouring process to the appearance of the vortex;

[0047] S330: The measured liquid level height is used as the critical slag lowering height, the measured vortex diameter is used as the slag lowering vortex diameter, and the recorded time is used as the slag lowering time.

[0048] When a vortex appears, the critical slag height (also known as the vortex critical height), the slag vortex diameter, and the slag discharge time can be determined based on the scale set on the ladle model. Once these data are obtained, they can be applied to actual production, allowing operators to know at what height the ladle liquid level is likely to cause a vortex, and to take appropriate measures to prevent slag from entering the crystallizer. In addition, researchers can also use this data to analyze the formation of vortices and develop measures to prevent vortex formation.

[0049] Furthermore, before step S100, the method further includes:

[0050] S010. Constructing the water simulation experimental model, wherein the water simulation experimental model includes a ladle model, a sliding gate arranged at the bottom of the ladle model, and a tundish model.

[0051] Furthermore, the step S010 specifically includes:

[0052] S011. Measure the actual ladle size and the actual tundish size;

[0053] S012. Converting the actual ladle size and the actual tundish size into the ladle model size and the tundish model size, respectively, according to a preset ratio;

[0054] S013. Construct the water simulation experiment model according to the size of the ladle model and the size of the tundish model.

[0055] To accurately simulate the pouring process, according to the similarity principle of water model experiments, each component of the experimental model needs to have the same shape as the actual device and be manufactured using a unified conversion ratio. The water simulation experimental model includes a ladle model, a sliding nozzle, a tundish model, and other necessary facilities such as a crystallizer. During the pouring process, when the sliding nozzle is opened, the experimental liquid (water) is injected from the ladle model into the tundish model; after the liquid level in the tundish model reaches the predetermined position, pouring begins. At this time, the tundish model not only receives the water injected by the ladle model, but also injects water into the downstream crystallizer.

[0056] Furthermore, before step S100, the method further includes:

[0057] S020. Obtain liquid level control parameters for simulating ladle pouring, where the liquid level control parameters include an initial liquid level height of the ladle model and an expected liquid level height of the tundish model.

[0058] Furthermore, the step S020 specifically includes:

[0059] S021. Obtaining an actual initial liquid level of the ladle and an actual expected liquid level of the tundish through an actual ladle pouring test;

[0060] S022. According to a preset ratio, the actual initial liquid level height of the ladle and the actual expected liquid level height of the tundish are converted into the initial liquid level height of the ladle model and the expected liquid level height of the tundish model, respectively.

[0061] Due to the harsh on-site environment, workers were unable to directly measure the molten steel level. Therefore, an indirect method was used to obtain this information: Step 1: Extract the curve of the ladle and its total weight during the first casting heat from the continuous casting machine's primary system. Step 2: Subtract the ladle's own weight to obtain the net weight of the molten steel. Based on the ladle's shape and dimensions, calculate the actual molten steel level hlad,p (i.e., the actual initial ladle level, also represented by h0, in meters). The same method was then used to determine the actual molten steel level htun,p (i.e., the expected tundish level, in meters) during the casting process. Then, using a conversion ratio, the actual molten steel level hlad,p was converted to the ladle model's initial level hlad,m, and the actual molten steel level htun,p was converted to the expected tundish model level htun,m. These two parameters were then used in preliminary experiments.

[0062] Furthermore, the step S210 specifically includes:

[0063] S211. A servo motor, an electric cylinder and a connecting rod are used to form the sliding gate adjustment device.

[0064] The sliding gate in this application consists of three main components: a slide plate, a slide plate groove, and a connecting rod. The slide plate and the slide plate groove each have a 22mm-diameter circular casting hole in the middle. The slide plate is connected to the connecting rod, and pulling the connecting rod allows the slide plate to move within the slide plate groove. The misalignment of the casting holes in the slide plate and the slide plate groove changes the slide plate's opening, representing the change in the sliding gate opening.

[0065] The sliding gate automatic control system designed in this invention is based on the principles of a servo system. Specifically, the control principle is as follows: a sliding plate is used as the control object, and an electric cylinder is connected to a connecting rod. The electric cylinder pushes the slide rod to control the slide's movement, thereby changing the sliding gate opening and achieving flow control. The flow control system's motion module consists of a sliding plate, servo motor, controller, reducer, and electric cylinder.

[0066] The technical core of the sliding gate adjustment device lies in the servo control system. This is an electrical control system based on the theory of automatic control. Structurally, the servo system consists of three main components: a servo motor, a controller, and a power drive. A servo motor is an indirect speed-changing device that converts voltage signals into torque and speed. Through vector control, it enables high-precision speed and position control. The servo motor is both the system's power source and the controlled object. The controller is the core of the servo system, controlling the motor's torque, speed, and angle of rotation, converting electrical energy into mechanical energy. Furthermore, the controller's feedback detection function detects the motor's actual position and, by determining whether the difference between the actual value and the control system's setpoint meets the required accuracy, performs position compensation, and thus achieves high-precision speed and position control. The power drive primarily performs a signal conversion function in the servo system. It converts the constant voltage and frequency grid power into the AC or DC power required by the motor and transmits signals from the controller to the servo motor, which adjusts torque according to the controlled variable, converting mechanical energy.

[0067] Servo motors can only rotate, but the slide-type flow control process requires linear motion to adjust the opening of the sliding gate. Therefore, in addition to the servo control system, a mechanical device that can convert rotational motion into linear motion is also required. An electric cylinder is a mechanical device based on the principle of screw transmission. Equipped with a motor, it can convert rotational motion into linear motion. Therefore, an electric cylinder is used to connect the connecting rod in this application. The electric cylinder and motor move synchronously, converting the servo motor's precise speed control into precise speed control, precise rotation control into precise position control, and precise torque control into precise thrust control.

[0068] The control module hardware for the sliding gate adjustment device consists of a CDHD driver and a computer, and the software primarily consists of ServoStudio. The CDHD driver establishes serial communication with the computer, and ServoStudio software implements the human-machine interface. The servo driver operates by converting the data signals transmitted by the computer into vector signals for the motor. These vector signals are then transmitted to the servo motor in the form of instructions, which the motor then operates according to. Furthermore, the controller receives feedback on the actual motor position after each instruction is executed. It then determines whether the difference between the actual position and the control system's setpoint meets the required accuracy, and then performs position compensation, thereby achieving high-precision speed and position control.

[0069] Furthermore, in step S130, a dichotomy method is used to determine the adjustment value of the sliding gate.

[0070] To obtain the accurate sliding gate opening value at each moment during the preliminary experiment, this experiment uses a dichotomy method to determine the appropriate slide movement distance (i.e., sliding gate opening). The final appropriate opening value is determined by continuously narrowing the slide opening range. The initial opening range of the dichotomy experiment is 0-100%. The following is a detailed explanation of the aforementioned method for simulating ladle pouring slag discharge using a specific example:

[0071] In this specific example, the water simulation experimental device mainly includes a ladle model, a tundish model, a sliding gate model, etc., and is equipped with a sliding gate adjustment device (flow control system). In this example, after proportional conversion to the actual production equipment, the molten pool depth of the ladle model is determined to be 1283mm, and the cross-sectional area is 1.05m 2 , a water tank with a height of 610 mm was used as the tundish model.

[0072] Step 1: Control of the slide opening during unsteady-state pouring:

[0073] First, open the water valve to raise the liquid level in the ladle model to 1100mm, reaching the full ladle state. At this time, the sliding gate of the ladle model is closed. After standing for 15 minutes, open the sliding gate and start pouring. The liquid level in the tundish model begins to rise. After 3 minutes and 40 seconds, the liquid level in the tundish model rises to 403mm, which is the ideal pouring height. At this time, the liquid level in the ladle model is 730mm. Figure 2 The liquid level changes of the ladle model and the tundish model during this process are shown.

[0074] Depend on Figure 2 It can be seen that at the beginning, the liquid level of the ladle model drops relatively quickly, and then relatively slowly. This is because the liquid level of the ladle model is relatively high at the beginning, and the flow rate at the sliding gate is relatively large; as the pouring proceeds, the liquid level of the ladle model decreases, and the flow rate at the sliding gate slowly decreases. During this process, the sliding gate opening is 100%. This process can be expressed by the following formula:

[0075]

[0076] Wherein, d0 is the diameter of the ladle model, in m;

[0077] h lad is the liquid level height of the ladle model, in m;

[0078] v0 is the liquid flow rate at the sliding gate, in m / s;

[0079] h0 is the initial liquid level height of the ladle model, in m;

[0080] t is time in seconds;

[0081] s is the cross-sectional area of ​​the ladle model, in m 2 .

[0082] It can be concluded from formula (1) that the speed at which the liquid level of the ladle model drops decreases as the pouring proceeds.

[0083] During the unsteady-state pouring process, the submerged nozzles are all closed, and the liquid in the ladle model enters the tundish model, causing the liquid level in the tundish model to rise. Equation (2) reflects the change in the liquid level of the tundish model. v0 decreases continuously as the pouring proceeds, so the rising speed of the liquid level in the tundish model decreases continuously.

[0084]

[0085] Where S1 is the cross-sectional area of ​​the tundish model, in m 2 ;

[0086] h tun is the liquid level height of the tundish model, in m.

[0087] The experiment found that when the liquid level of the tundish model rises to the ideal height, if the slide opening is kept at 100%, the liquid level in the tundish model will rise. The proof is as follows: From formula (3), it can be obtained that the liquid level of the ladle model h lad =0.73m, sliding nozzle diameter d = 0.022m; liquid level in the tundish model h tun =0.403m, the diameter of the tundish model nozzle d1 = 0.0142m, the flow rate entering the tundish model is greater than the flow rate flowing out of the tundish model, so the liquid level in the tundish model will continue to rise.

[0088]

[0089] Where, d is the diameter of the sliding nozzle, in m;

[0090] Q0 is the flow rate entering the intermediate package model, in m 3 / h;

[0091] Q1 is the flow rate out of the tundish model, in m 3 / h;

[0092] ρ is the density of the test liquid, in kg / m 3 ;

[0093] g is the acceleration due to gravity, which is 9.8 m / s 2 .

[0094] To prevent the liquid level in the tundish model from rising, the only way to stabilize the liquid level inside the tundish model is to reduce the sliding gate opening and the flow rate at the sliding gate. This experiment uses a dichotomy method to determine the appropriate sliding gate opening, and the final appropriate opening value is determined by continuously narrowing the sliding gate opening range.

[0095] The initial opening range for the dichotomy experiment was {0-100%}. The tundish model liquid level stability range was determined based on actual on-site tundish level fluctuations. The experimental tundish level fluctuation accuracy was calculated based on recorded tundish weight data during the pouring process. This means that if the slide plate opening ensures that the tundish model liquid level fluctuations are within the range of (403 ± 2.5 mm), the appropriate gate opening is achieved. After repeated experiments, the slide plate opening k was determined to be 39.5%, achieving a stable tundish level of 403 mm.

[0096] To summarize, during the non-steady-state pouring process, after the ladle is at rest, the sliding gate is opened immediately, and the slide opening is maintained at 100%. When the molten steel raises the liquid level of the tundish to the ideal height of 403 mm, the tundish gate is opened (to start pouring), and at the same time, the ladle sliding gate opening is adjusted to k = 39.5% to prepare for steady-state casting. Figure 3 The change of sliding gate opening during the non-steady-state casting process.

[0097] Step 2: Control of the slide opening during steady-state pouring:

[0098] After the unsteady-state pouring process concludes, the steady-state pouring process begins. During this process, the liquid level in the tundish model must remain stable within a range of 403 ± 2.5 mm until the pouring is complete. The experiment consists of two parts: first, the slide opening is manually adjusted to maintain a stable liquid level in the tundish model, and the changes in the slide opening and the tundish model liquid level during the steady-state pouring process are recorded. Then, the recorded slide opening change data is compiled into a CDHD driver script command to generate an automatic slide flow control program. Running this flow control program during the pouring process enables controlled movement of the slide, thereby automatically controlling the sliding gate opening.

[0099] At the end of the unsteady-state pouring, the slide opening was set to k = 39.5%, and the liquid level in the tundish model remained stable. As the pouring continued, the liquid level in the tundish model dropped to 400 mm after 50 seconds, while the liquid level in the ladle model was 702 mm. Analysis revealed that the drop in the ladle model liquid level reduced the molten steel velocity at the sliding gate, resulting in a decrease in flow at the sliding gate. In this case, the sliding gate opening needed to be increased to stabilize the flow at the sliding gate. Setting the slide opening to k = 50% revealed a rapid rise in the tundish model liquid level, indicating that the selected sliding gate opening was too large. Therefore, the slide opening for the next cycle was set between 39.5% and 50%. The experiment continued to use a binary approach to determine the slide opening for the next cycle, with the initial opening range set at {39.5% to 50%}. After repeatedly narrowing the opening range, the slide opening for the second cycle was ultimately determined to be k2 = 40.1%.

[0100] The above experiment was repeated. After 1275 seconds, the ladle model was cast. The slide stroke, sliding gate opening, liquid level of the ladle model and liquid level of the tundish model were recorded in each cycle.

[0101] Figure 4 This is a comprehensive schematic diagram of the changes in the sliding gate opening of the ladle model, the liquid level of the ladle model, and the liquid level of the tundish model during the steady-state pouring process. As can be seen from the figure, after adopting this method for dynamic control of the sliding gate, the liquid level of the tundish model remains essentially unchanged during the steady-state pouring process, appearing as a substantially horizontal straight line on the graph; while the liquid level within the ladle model decreases at an approximately uniform rate. Simultaneously, the sliding gate opening gradually increases, and the corresponding gate opening curve presents a gradually increasing curve. The curve becomes steeper as it extends to the right, i.e., the first half (left side) of the curve approximates a 45° slope or a straight line with a slope of 1. In the second half of the steady-state pouring process, i.e., to the right of the intersection of the liquid level decrease curve within the ladle model and the curve of the gradually increasing gate opening, the opening change gradually increases, causing the slope of the curve to also gradually increase. Through fitting and regression methods, the gate opening curve becomes or approximates a parabola. This is consistent with the conclusion of the proof, indicating that the designed sliding gate adjustment device (flow control system) meets the experimental requirements and can control the sliding gate opening to stabilize the liquid level of the ladle model, thereby accurately simulating the steady-state pouring process of the ladle.

[0102] During the pouring process, the opening of the sliding nozzle changes continuously, increasing from 39.5% to 58.5%. This is because the liquid level in the ladle model continues to drop during the pouring process, and the flow rate at the sliding nozzle continues to decrease. To maintain the flow rate at the sliding nozzle unchanged, it is necessary to continuously increase the opening of the sliding nozzle; in the early stage of pouring, the opening of the sliding nozzle increases at an approximately uniform speed, and in the later stage of pouring, the rate of increase of the opening of the sliding nozzle accelerates. This is because a vortex is generated near the sliding nozzle at the end of pouring, and the vortex inhales air, causing air to be mixed with the molten steel, and the volume of liquid flowing into the ladle model per unit time is reduced. Therefore, the growth rate of the sliding nozzle opening must be increased to maintain the flow rate unchanged, thereby maintaining the liquid level in the ladle model stable.

[0103] The manual flow control experiment can obtain the change of the slide stroke during the steady-state casting process. According to the recorded data of the slide stroke, sliding gate opening, ladle model liquid level and tundish model liquid level of each cycle, the script command for controlling the slide stroke can be compiled. This experiment adopts the driver position loop control method, in which the motor speed is used to represent the slide position. When the motor speed is positive, the sliding gate opening decreases; when the motor speed is negative, the sliding gate opening increases. When the motor rotates 110r, the slide moves 22mm. Therefore, when the motor rotates 1 circle, the slide position changes by 0.2mm. At the beginning of steady-state casting, the motor needs to rotate 66.5r to reduce the opening to 39.5%. The slide flow control script command compiled according to the recorded data is as follows:

[0104] k: Disable the driver.

[0105] opmode8: Set the drive operation mode to "position mode".

[0106] acc5000: Sets the acceleration to 1000. The default unit is rpm / s.

[0107] Dec-00: Set the deceleration to 1000. The default unit is rpm / s.

[0108] en: driver enable

[0109] Moveinc66.5300: The motor rotates forward 66.5 rpm at 300 rpm, and the opening is reduced to 39.5%.

[0110] #Delay50000: The skateboard is open at 39.5% for 50 seconds

[0111] Moveinc-0.5300: The motor rotates negatively by 0.5r at a speed of 300r / min, and the opening increases to 40.1%

[0112] #Delay50000: The slide is open at 40.1% for 50 seconds

[0113] Moveinc-0.5300: The motor rotates negatively by 0.5r at a speed of 300r / min, and the opening increases to 40.5%

[0114] #Delay50000: The skateboard is open at 40.5% for 50 seconds

[0115] Moveinc-0.5300: The motor rotates negatively by 0.5r at a speed of 300r / min, and the opening increases to 40.9%

[0116] #Delay50000: The skateboard is open at 40.9% for 50 seconds

[0117] Moveinc-0.625300: The motor rotates negatively by 0.625r at a speed of 300r / min, and the opening increases to 41.4%

[0118] #Delay50000: The slide is open at 41.4% for 50 seconds

[0119] Moveinc-0.625300: The motor rotates negatively by 0.625r at a speed of 300r / min, and the opening increases to 42.3%

[0120] #Delay50000: The skateboard is open at 42.3% for 50 seconds

[0121] Moveinc-0.625300: The motor rotates negatively by 0.625r at a speed of 300r / min, and the opening increases to 42.7%

[0122] #Delay50000: The skateboard is open at 42.7% for 50 seconds

[0123] Moveinc-0.625300: The motor rotates negatively by 0.625r at a speed of 300r / min, and the opening increases to 43.2%

[0124] #Delay50000: The slide opening is 43.2% and maintained for 50sMoveinc-0.625300: The motor rotates negatively by 0.625r at 300r / min, and the opening increases to 43.6%

[0125] #Delay50000: The slide opening is 43.6% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 44.5%

[0126] #Delay50000: The slide opening is 44.5% and maintained for 50 seconds. Moveinc-0.75300: The motor rotates negatively by 0.75 revolutions at 300 r / min, and the opening increases to 45.0%.

[0127] #Delay50000: The slide opening is 45.0% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 45.9%

[0128] #Delay50000: The slide opening is 45.9% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 46.4%

[0129] #Delay50000: The slide opening is 46.4% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 47.3%

[0130] #Delay50000: The slide opening is 47.3% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 47.7%

[0131] #Delay50000: The slide opening is 47.7% and maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 48.6%

[0132] #Delay50000: The slide opening is 40.9% and the state is maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the slide opening increases to 49.1%#Delay50000: The slide opening is 49.1% and the state is maintained for 50sMoveinc-0.75300: The motor rotates negatively at 300r / min for 0.75r, and the opening increases to 50.0%

[0133] #Delay50000: The slide opening is 50.0% and maintained for 50sMoveinc-0.875300: The motor rotates negatively by 0.875r at 300r / min, and the opening increases to 50.9%

[0134] #Delay50000: The slide opening is 50.9% and maintained for 50sMoveinc-0.875300: The motor rotates negatively by 0.875r at 300r / min, and the opening increases to 51.4%

[0135] #Delay50000: The slide opening is 51.4% and maintained for 50 seconds. Moveinc-1300: The motor rotates negatively for 1 revolution at 300 r / min, and the opening increases to 52.3%.

[0136] #Delay50000: The slide opening is 52.3% and maintained for 50 seconds. Moveinc-1300: The motor rotates negatively for 1 revolution at 300 r / min, and the opening increases to 53.2%.

[0137] #Delay50000: The slide opening is 53.2% and maintained for 50 seconds. Moveinc-1300: The motor rotates negatively for 1 revolution at 300 r / min, and the opening increases to 54.1%.

[0138] #Delay50000: The slide is open at 54.1% for 50 seconds

[0139] Moveinc-1.25300: The motor rotates negatively by 1.25r at a speed of 300r / min, and the opening increases to 55.4%

[0140] #Delay50000: The slide opening is 55.4% and maintained for 50 seconds

[0141] Moveinc-1.5300: The motor rotates negatively by 1.5r at a speed of 300r / min, and the opening increases to 56.8%

[0142] #Delay50000: The skateboard is open at 56.8% for 50 seconds

[0143] Moveinc-1.5300: The motor rotates negatively for 2 r at 300 r / min, and the opening increases to 58.5%

[0144] #Delay75000: The slide is open at 58.5% and maintained for 75 seconds

[0145] k: Driver disabled

[0146] Enter the obtained program command into the script box in the "Terminal" of the ServoStudio software of the automatic flow control system. Running the program can convey the position control command to the driver. The driver automatically controls the movement of the electric cylinder, thereby controlling the movement of the slide, and then controlling the opening of the sliding gate to achieve the purpose of flow control. During the movement of the motor, run the recording and output program, and the motor revolutions are continuously input into the "Output" recording box. The data in the recording box can be used to track the motor movement position in a timely manner, thereby reflecting the changes in the movement position of the electric cylinder and the opening of the sliding gate. When running the automatic flow control program during the pouring process, it was found that the liquid level in the tundish model was stable within the range of 403±2.5mm. Therefore, running the automatic flow control program can stabilize the liquid level in the tundish model and achieve the purpose of steady-state pouring.

[0147] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. The appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0148] The above description of the disclosed embodiments is intended to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments presented herein but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0149] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for simulating ladle pouring and slag removal using a water simulation experiment, characterized in that: include: Obtain the sliding gate opening control curve through the water simulation experimental model; Simulating the ladle pouring process by using the water simulation experimental model and the sliding gate opening control curve; During the simulated ladle pouring process, determining slag discharging parameters for the ladle pouring, wherein the slag discharging parameters include a critical slag discharging height, a slag discharging vortex diameter, and a slag discharging time; The method of obtaining the sliding gate opening control curve through the water simulation experimental model specifically includes: Add water to the ladle model to the initial liquid level of the ladle model; Fully open the sliding gate at the bottom of the ladle model to allow water in the ladle model to flow into the tundish model; When the liquid level in the tundish model reaches the expected liquid level height of the tundish model, the opening of the sliding gate is dynamically adjusted so that the difference between the liquid level in the tundish model and the expected liquid level height of the tundish model is maintained within a preset variation range; The time when the liquid level in the tundish model reaches the expected liquid level height of the tundish is used as the first set time; Drawing a sliding gate opening control curve according to the data of the sliding gate opening changing with time; The method of simulating the ladle pouring process by using the water simulation experimental model and the sliding gate opening control curve specifically includes: A sliding gate adjustment device is provided on the water simulation test model; Adding water to the ladle model to an initial liquid level of the ladle model; Fully opening the sliding gate through the sliding gate adjusting device; After the first set time is reached, the sliding gate adjustment device is enabled to adjust the sliding gate opening in real time according to the sliding gate opening control curve.

2. The method for simulating ladle pouring slag using a water simulation experiment according to claim 1, characterized in that: In the simulated ladle pouring process, determining the slag setting parameters of the ladle pouring specifically includes: observing whether a vortex appears on the liquid surface in the ladle model; If a vortex appears on the liquid surface in the ladle model, the liquid surface height and the vortex diameter when the vortex appears in the ladle model are measured using a ruler, and the time taken from the start of the simulated ladle pouring process to the appearance of the vortex is recorded; The measured liquid level height is taken as the critical slag lowering height, the measured vortex diameter is taken as the slag lowering vortex diameter, and the recorded time is taken as the slag lowering time.

3. The method for simulating ladle pouring slag using a water simulation experiment according to claim 1, characterized in that: Before obtaining the sliding gate opening control curve through the water simulation experimental model, the method further includes: The water simulation experimental model is constructed, and the water simulation experimental model includes a ladle model and a tundish model.

4. The method for simulating ladle pouring and slag removal using a water simulation experiment according to claim 1, characterized in that: Before obtaining the sliding gate opening control curve through the water simulation experimental model, the method further includes: Liquid level control parameters for simulating ladle pouring are obtained, wherein the liquid level control parameters include an initial liquid level height of the ladle model and an expected liquid level height of the tundish model.

5. The method for simulating ladle pouring and slag removal using a water simulation experiment according to claim 3, characterized in that: The construction of the water simulation experimental model specifically includes: Measure actual ladle size and actual tundish size; According to a preset ratio, the actual ladle size and the actual tundish size are converted into the ladle model size and the tundish model size respectively; The water simulation experiment model is constructed according to the ladle model size and the tundish model size.

6. The method for simulating ladle pouring and slag removal using a water simulation experiment according to claim 4, characterized in that: Get the liquid level control parameters for simulated ladle pouring, including: Obtain the actual initial liquid level of the ladle and the expected liquid level of the tundish through actual ladle pouring tests; According to a preset ratio, the actual initial liquid level height of the ladle and the actual expected liquid level height of the tundish are converted into the initial liquid level height of the ladle model and the expected liquid level height of the tundish model, respectively.

7. The method for simulating ladle pouring and slag removal using a water simulation experiment according to claim 3, characterized in that: The sliding gate adjustment device is provided on the water simulation test model, specifically comprising: The sliding gate adjustment device is constructed by using a servo motor, an electric cylinder and a connecting rod.

8. The method for simulating ladle pouring and slag removal using a water simulation experiment according to claim 1, characterized in that: In the process of dynamically adjusting the opening of the sliding gate to keep the difference between the liquid level in the tundish model and the expected liquid level height of the tundish model within a preset variation range, a dichotomy method is used to determine the adjustment value of the sliding gate.

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