A method for predicting the depth of the molten pool during converter smelting

Abstract

The present invention discloses a method for predicting the depth of the molten pool liquid level during converter smelting, belonging to the technical field of steel metallurgy. The method is calculated according to the oxygen supply intensity and blowing time by a formula; the formula is: ; In the formula, B is the depth of the molten pool liquid level during converter smelting, unit: cm; B1 is the depth of the molten pool liquid level under a new furnace operation, unit: cm; t1 is the blowing time under standard conditions, unit: min; t is the actual blowing time, unit: min; k is a coefficient related to the nominal capacity of the converter, and the value is 1.02 when the nominal capacity of the converter is 100 tons, 1.06 when it is 120 tons, and 1.1 when it is 260 tons; r is the actual oxygen supply intensity, unit: Nm 3 / (min·t); r0 is the oxygen supply intensity under standard conditions, unit is Nm 3 / (min·t). The present invention can achieve accurate prediction of the molten pool liquid level depth.

Description

Technical Field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a method for predicting the liquid level depth of a molten pool during a converter smelting process. Background Art

[0002] During the converter steelmaking process, the depth of the melt pool directly impacts the smelting results. In a top-blown oxygen converter, the melt pool depth is controlled by adjusting the lance position to achieve decarburization, dephosphorization, and temperature increase. Changes in the melt pool depth affect the flow and chemical reaction uniformity of the molten steel, thus affecting the quality of the final steel. The melt pool depth also determines the impact depth and area of ​​the oxygen lance jet, which significantly influences the stirring effect and composition homogenization of the melt pool. Safety: Accurate measurement of the melt pool depth helps optimize the charging schedule, ensuring a proper iron-to-scrap ratio and avoiding the degradation of economic and technical indicators caused by excessive or insufficient charging. Furthermore, by measuring the melt pool depth, lining erosion can be predicted, providing data support for furnace management, extending furnace life, and reducing production costs. Furthermore, the melt pool depth influences the control of parameters such as molten steel tapping rate and alloy absorption rate. Therefore, melt pool depth is a crucial factor influencing smelting process parameters.

[0003] In actual operation, the common methods for measuring the molten pool liquid level depth are physical methods or online measurement by adding equipment and systems. These methods are time-consuming and labor-intensive, costly, and have low measurement accuracy.

[0004] Patent application number CN202410579744.7 provides a method for calculating the depth of the converter bath. Blast furnace iron is added to the converter, the converter iron level is measured, and the depth of the converter bath is calculated based on the measured level. This method measures the molten steel bath level based on the measured iron level, but does not fundamentally address the complex, time-consuming, and labor-intensive measurement process.

[0005] Patent application number CN202411724755.6 provides a system and method for online monitoring of the melt pool surface level. The system includes a data acquisition module, a data preprocessing module, a model training and optimization module, an angle detection and compensation module, a nonlinear data processing module, a system testing and optimization module, as well as a display module, a communication module, and a control module. This method uses related equipment to measure the melt pool surface level, significantly increasing steelmaking costs and making equipment maintenance difficult, impacting the overall profitability of the steel mill.

[0006] The patent application with application number CN202311721505.2 provides a method for predicting the liquid level of the converter molten pool, which realizes the liquid level of the converter molten pool based on data such as the actual loading amount of the converter and the metal material recovery rate; however, the loading amount, metal material recovery rate, etc. will vary from furnace to furnace, and the accuracy of calculating the molten pool liquid level using these variable parameters is poor.

[0007] Patent application number CN202411827832.0 proposes a method for improving the accuracy of melt pool level calculations using a converter's secondary model. By comparing the calculated melt pool level using the converter's secondary model with the measured level using the auxiliary lance, the actual melt pool level is corrected and determined. This method places high demands on on-site equipment, software systems, and data; without this data, predictions cannot be achieved. Summary of the Invention

[0008] The present invention aims to provide a method for predicting the depth of the molten pool liquid level during the converter smelting process, which can accurately predict the depth of the molten pool liquid level during the converter smelting process.

[0009] To achieve the above purpose, the technical solution of the present invention is as follows:

[0010] A method for predicting the depth of the molten pool during converter smelting is calculated based on the oxygen supply intensity and blowing time using the formula: .

[0011] In the formula, B is the depth of the molten pool during the converter smelting process, in cm; B1 is the depth of the molten pool in the case of a new furnace, in cm; t1 is the blowing time under standard conditions, in min; t is the actual blowing time, in min; k is a coefficient related to the nominal capacity of the converter, which is 1.02 when the nominal capacity of the converter is 100 tons, 1.06 when the nominal capacity of the converter is 120 tons, and 1.1 when the nominal capacity of the converter is 260 tons; r is the actual oxygen supply intensity, in Nm 3 / (min·t); r0 is the oxygen supply intensity under standard conditions, unit is Nm 3 / (min·t).

[0012] Furthermore, the blowing time under standard conditions described in the present invention is calculated based on actual oxygen consumption and oxygen flow rate under the conditions of a new converter operation; the specific calculation formula is: t1=Q / V, where Q is the actual oxygen consumption under the conditions of a new converter operation, in Nm 3 , V is the oxygen flow rate under the new converter service conditions, unit is Nm³ / min.

[0013] Furthermore, the oxygen supply intensity under standard conditions described in the present invention is calculated based on actual oxygen consumption, blowing time and charging amount under the conditions of a new converter operation. The specific calculation formula is: r0=Q / (t1*W), where Q is the actual oxygen consumption, unit Nm 3 , t1 is the blowing time under standard conditions, the unit is min, W is the metal charging amount, the unit is t.

[0014] Furthermore, the method of the present invention is not suitable for smelting in special circumstances such as recycled steel.

[0015] The beneficial effects of adopting the above technical solution are:

[0016] Compared with conventional physical measurements and the addition of online measuring equipment, the present invention takes a unique approach. By systematically analyzing relevant data such as blowing time and oxygen supply intensity and determining the optimal prediction parameters, it provides a more realistic method for predicting the liquid level depth of the converter melt pool, laying the foundation for precise control of steelmaking raw data and processes.

[0017] The method of the present invention can accurately predict the depth of the molten pool level and can be applied on a large scale in the steelmaking process. It is simple to operate and has stable results. Compared with traditional steelmaking processes, the method of the present invention can effectively predict the depth of the molten pool, provide accurate data support for process control, effectively improve the control capability of the steelmaking process, and have huge social and economic benefits. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] In each embodiment, the calculation formula for the depth of the molten pool liquid level during the converter smelting process is:

[0020] .

[0021] Where: B is the depth of the molten pool during converter smelting, in cm; B1 is the depth of the molten pool under new operation, in cm; t1 is the blowing time under standard conditions, in min; t is the actual blowing time, in min; k is a coefficient related to the nominal capacity of the converter, which is 1.02 when the nominal capacity of the converter is 100 tons, 1.06 when it is 120 tons, and 1.1 when it is 260 tons; r is the actual oxygen supply intensity, in Nm 3 / (min·t); r0 is the oxygen supply intensity under standard conditions, unit is Nm 3 / (min·t).

[0022] Under standard conditions, the calculation formulas for blowing time t1 and oxygen supply intensity r0 are as follows:

[0023] t1=Q / V, where Q is the actual oxygen consumption in Nm 3 , V is the oxygen flow rate, unit is Nm³ / min.

[0024] r0=Q / (t1*W), where Q is the actual oxygen consumption in Nm 3 , t1 is the blowing time under standard conditions, in min, W is the metal charge, in t;

[0025] For converters of different nominal capacities in the examples, the oxygen supply intensity and blowing time under standard conditions are as follows:

[0026] (1) For a 100-ton converter, under standard conditions, the metal charge W is 120 tons and the actual oxygen consumption Q is 4992 Nm 3 , the oxygen flow rate V is 384 Nm³ / min, according to the calculation formula:

[0027] Under standard conditions, blowing time t1=Q / V=4992 Nm 3 / 384 Nm³ / min=13min;

[0028] Under standard conditions, oxygen supply intensity r0=Q / (t1*W)=4992 Nm 3 / (13min*120t) = 3.2 Nm 3 / (min·t);

[0029] (2) For a 120-ton converter, under standard conditions, the metal charge W is 140 t and the actual oxygen consumption Q is 7350 Nm 3 , the oxygen flow rate V is 490 Nm³ / min, according to the calculation formula:

[0030] Under standard conditions, blowing time t1=Q / V=7350 Nm 3 / 490 Nm³ / min=15min;

[0031] Under standard conditions, oxygen supply intensity r0=Q / (t1*W)=7350 Nm 3 / (15min*140t) = 3.5 Nm 3 / (min·t);

[0032] (3) For a 260-ton converter, under standard conditions, the metal charge W is 290t and the actual oxygen consumption Q is 22040Nm 3, the oxygen flow rate V is 1102 Nm³ / min, according to the calculation formula:

[0033] Under standard conditions, blowing time t1=Q / V=22040 Nm 3 / 1102 Nm³ / min=20min;

[0034] Under standard conditions, oxygen supply intensity r0=Q / (t1*W)=22040 Nm 3 / (20min*290t) = 3.8 Nm 3 / (min·t).

[0035] Example 1

[0036] This embodiment is a 120-ton converter. In a new operation, the molten pool liquid level B1 is 160 cm. k is a coefficient related to the nominal capacity, and its value is 1.06.

[0037] During the smelting process, the actual oxygen supply intensity r is 3.4Nm 3 / (min·t), the actual blowing time t is 15.8min. Under standard conditions, the oxygen supply intensity r0 is 3.5Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 15min.

[0038] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 161.76 cm.

[0039] The actual measured depth of the molten pool liquid level is 160.79 cm, which deviates from the actual value by 0.97 cm and has an error ratio of 0.6%, indicating that the formula is reliable and effective.

[0040] Example 2

[0041] This embodiment is a 120-ton converter, and the depth of the molten pool liquid level is 160 cm in a new operation; k is a coefficient related to the nominal capacity, and its value is 1.06.

[0042] During the smelting process, the actual oxygen supply intensity r is 3.6Nm 3 / (min·t), the actual blowing time t is 14.5min. Under standard conditions, the oxygen supply intensity r0 is 3.5Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 15min.

[0043] Substituting each parameter into the formula, it is calculated that the depth of the converter molten pool under the above process conditions is 160.6 cm.

[0044] The actual measured depth of the molten pool liquid level is 161.76 cm, with a deviation of -1.16 cm from the actual value and an error ratio of 0.72%, indicating that the formula is reliable and effective.

[0045] Example 3

[0046] This embodiment is a 120-ton converter, and the depth of the molten pool liquid level is 160 cm in a new operation; k is a coefficient related to the nominal capacity, and its value is 1.06.

[0047] During the smelting process, the actual oxygen supply intensity r is 3.7Nm 3 / (min·t), the actual blowing time t is 13.5min. Under standard conditions, the oxygen supply intensity r0 is 3.5Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 15min.

[0048] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 159.52 cm.

[0049] The actual measured depth of the molten pool liquid level is 158.92 cm, which deviates from the actual value by 0.6 cm and has an error ratio of 0.38%, indicating that the formula is reliable and effective.

[0050] Example 4

[0051] This embodiment is a 100-ton converter, and the depth of the molten pool liquid level is 140 cm in a new operation; k is a coefficient related to the nominal capacity, and its value is 1.02.

[0052] During the smelting process, the actual oxygen supply intensity r is 3.1Nm 3 / (min·t), the actual blowing time t is 13.5min. Under standard conditions, the oxygen supply intensity r0 is 3.2Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 13min.

[0053] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 141.44 cm.

[0054] The actual measured depth of the molten pool liquid level is 142.92 cm, with a deviation of -1.48 cm from the actual value and an error ratio of 1.04%, indicating that the formula is reliable and effective.

[0055] Example 5

[0056] This embodiment is a 100-ton converter, and the depth of the molten pool liquid level is 140 cm in a new operation; k is a coefficient related to the nominal capacity, and its value is 1.02.

[0057] During the smelting process, the actual oxygen supply intensity r is 3.3Nm 3 / (min·t), the actual blowing time t is 12.5min. Under standard conditions, the oxygen supply intensity r0 is 3.2Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 13min.

[0058] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 140.56 cm.

[0059] The actual measured depth of the molten pool liquid level is 141.62 cm, with a deviation of -1.06 cm from the actual value and an error ratio of 0.75%, indicating that the formula is reliable and effective.

[0060] Example 6

[0061] This embodiment is a 100-ton converter, and the depth of the molten pool liquid level is 140 cm in a new operation; k is a coefficient related to the nominal capacity, and its value is 1.02.

[0062] During the smelting process, the actual oxygen supply intensity r is 3.35Nm 3 / (min·t), the actual blowing time t is 12min. Under standard conditions, the oxygen supply intensity r0 is 3.2Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 13min.

[0063] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 140.56 cm.

[0064] The actual measured depth of the molten pool liquid level is 142.84 cm, with a deviation of -2.82 cm from the actual value and an error ratio of 1.97%, indicating that the formula is reliable and effective.

[0065] Example 7

[0066] This embodiment is a 260-ton converter, and the depth of the molten pool liquid level is 200 cm in the case of a new furnace operation; k is a coefficient related to the nominal capacity, and its value is 1.1.

[0067] During the smelting process, the actual oxygen supply intensity r is 3.9Nm 3 / (min·t), the actual blowing time t is 18.5min. Under standard conditions, the oxygen supply intensity r0 is 3.8Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 20min.

[0068] Substituting each parameter into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 199.54 cm.

[0069] The actual measured depth of the molten pool liquid level is 196.66 cm, which deviates from the actual value by 2.88 cm and has an error ratio of 1.46%, indicating that the formula is reliable and effective.

[0070] Example 8

[0071] This embodiment is a 260-ton converter, and the depth of the molten pool liquid level is 200 cm in the case of a new furnace operation; k is a coefficient related to the nominal capacity, and its value is 1.1.

[0072] During the smelting process, the actual oxygen supply intensity r is 3.7Nm 3 / (min·t), the actual blowing time t is 21.5min. Under standard conditions, the oxygen supply intensity r0 is 3.8Nm 3 / (min·t), under standard circumstances, the blowing time t1 is 20min.

[0073] Substituting various parameters into the formula, it is calculated that the liquid level depth of the converter molten pool under the above process conditions is 202.44 cm.

[0074] The actual measured depth of the molten pool liquid level is 197.65 cm, which deviates from the actual value by 4.79 cm and has an error ratio of 2.42%, indicating that the formula is reliable and effective.

[0075] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for predicting the depth of the molten pool during converter smelting, characterized in that: According to the oxygen supply intensity and blowing time, it is calculated by the formula: ; In the formula: B is the depth of the molten pool liquid level during the converter smelting process, unit: cm; B1 is the depth of the molten pool liquid level under the condition of a new furnace, unit: cm; t1 is the blowing time under standard conditions, unit: min; t is the actual blowing time, unit: min; k is a coefficient related to the nominal capacity of the converter, which is 1.02 when the nominal capacity of the converter is 100 tons, 1.06 when it is 120 tons, and 1.1 when it is 260 tons; r is the actual oxygen supply intensity, unit: Nm 3 / (min·t); r0 is the oxygen supply intensity under standard conditions, unit is Nm 3 / (min·t).

2. The method for predicting the depth of the molten pool during converter smelting according to claim 1, characterized in that: Under the standard conditions, blowing time t1=Q / V, where Q is the actual oxygen consumption in Nm 3 , V is the oxygen flow rate, unit is Nm³ / min.

3. The method for predicting the depth of the molten pool during converter smelting according to claim 1, characterized in that: Under the standard conditions, the oxygen supply intensity r0=Q / (t1*W), where Q is the actual oxygen consumption, in Nm 3 , t1 is the blowing time under standard conditions, the unit is min, W is the metal charging amount, the unit is t.

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