Method for stably controlling oxygen pressure in steelmaking process

Abstract

The invention provides a method for stably controlling oxygen pressure in a steelmaking process, which comprises the following steps: S1) according to the working condition of a converter, different static models are formulated, and the static models are corresponding models of oxygen flow, material distribution, lance position and oxygen pressure in different steelmaking stages; s2) in the blowing stage, setting different oxygen flows; establishing oxygen regulating valve opening degree data corresponding to the oxygen flow rate achieved under different oxygen header pipe pressures; and S3) when the used oxygen pressure is different from the target oxygen pressure, adjusting the opening degree of the oxygen adjusting valve according to the opening degree data of the oxygen adjusting valve so as to enable the used oxygen pressure to be the same as the target oxygen pressure. According to the method, the oxygen regulating valve opening degree data corresponding to the oxygen flow and the oxygen header pipe pressure are established, the oxygen regulating valve opening degree is adjusted according to the oxygen regulating valve data when the used oxygen pressure is different from the target oxygen pressure, the used oxygen pressure is consistent with the target oxygen pressure, and therefore the oxygen pressure can be stably controlled.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy and steelmaking, and in particular to a method for stably controlling oxygen pressure in a steelmaking process. Background Art

[0002] Converter steelmaking is a steelmaking process that uses molten iron, scrap steel, and ferroalloys as the main raw materials. It does not rely on external energy sources, but relies on the physical heat of the molten iron itself and the chemical reaction between the components of the molten iron to generate heat. Oxygen top-blown furnace steelmaking is a conventional converter steelmaking method. Specifically, according to the requirements of the ingredients, scrap steel is first loaded into the furnace, then molten iron is poured in, and an appropriate amount of slag-making materials (such as quicklime, etc.) are added; after adding the ingredients, an oxygen spray gun is inserted into the furnace from the top of the furnace to blow oxygen (high-pressure oxygen flow with a purity greater than 99%) so that it directly reacts with the high-temperature molten iron to oxidize and remove impurities; after removing most of the sulfur and phosphorus, when the composition and temperature of the molten steel meet the requirements, the blowing is stopped, the spray gun is lifted, and steel is ready to be tapped; when tapping, the furnace body is tilted, and the molten steel is injected into the ladle from the tapping port, and a deoxidizer is added to deoxidize and adjust the composition; after the molten steel is qualified, it can be cast into steel castings or ingots, and the ingots can be rolled into various steel products.

[0003] In the converter steelmaking process, oxygen supply pressure and oxygen flow rate play a key role in the smelting process. Unstable oxygen supply pressure will affect the stirring of the molten pool by the oxygen lance. When the oxygen pressure used is higher than the oxygen pressure set by the model, it will lead to "hard blowing", which will cause the iron oxide in the slag to be digested quickly and cause drying out; when the oxygen pressure used is lower than the oxygen pressure set by the model, it will lead to "soft blowing", which will cause the iron oxide in the slag to accumulate and cause splashing when the temperature rises; the fluctuation of oxygen pressure during the blowing process is not conducive to the control of the smelting process and cannot accelerate the advancement of the intelligent steelmaking project.

[0004] In view of the above situation, it is of great significance to provide a method for stably controlling the oxygen pressure in the steelmaking process. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a method for stably controlling the oxygen pressure in the steelmaking process. The method provided in this application can achieve the purpose of stabilizing the oxygen pressure in the smelting process.

[0006] In view of this, the present application provides a method for stably controlling oxygen pressure in a steelmaking process, comprising the following steps:

[0007] S1) formulating different static models according to converter operating conditions, wherein the static models are corresponding models of oxygen flow, distribution, gun position and oxygen pressure in different steelmaking stages;

[0008] S2) During the blowing stage, different oxygen flow rates are set;

[0009] Establish oxygen regulating valve opening data corresponding to oxygen flow rate under different oxygen main pipe pressures;

[0010] S3) When the used oxygen pressure is different from the target oxygen pressure, adjusting the oxygen regulating valve opening according to the oxygen regulating valve opening data to make the used oxygen pressure the same as the target oxygen pressure.

[0011] In some specific embodiments, in step S1), the converter operating conditions include molten iron conditions, scrap steel structure and target steel grade.

[0012] In some specific embodiments, the molten iron conditions include high-temperature high-silicon molten iron, low-temperature low-silicon molten iron, and low-temperature high-silicon molten iron.

[0013] In some specific embodiments, in step S1), the range of the gun position is 1250-1700 mm.

[0014] In some specific embodiments, in step S1), the gun position is 1250mm, 1350mm, 1400mm, 1450mm, 1500mm, 1550mm, 1600mm, or 1700mm.

[0015] In some specific embodiments, in step S1), the cloth material includes one or more of lime, limestone, raw dolomite, dust ash briquettes and soybean steel.

[0016] In some specific embodiments, in step S2), Q represents the oxygen flow rate, and the unit is m 3 / h, and the value range of the oxygen flow rate includes: Q≤3000, 3000<Q≤3100, 3100<Q≤3200, 3200<Q≤3300, 3300<Q≤3400, 3400<Q≤3500, 3500<Q≤3600, 3600<Q≤3700, 3700<Q≤3800, 3800<Q≤3900, 3900<Q≤4000.

[0017] In some specific embodiments, the oxygen pressure range corresponding to each value interval of the oxygen flow rate includes: 0.0<P≤1.2MPa, 1.2MPa<P≤1.25MPa, 1.25MPa<P≤1.30MPa, 1.30MPa<P≤1.40MPa, 1.40MPa<P≤1.50MPa, 1.50MPa<P≤1.60MPa, 1.60MPa<P≤1.70MPa, 1.70MPa<P≤1.80MPa, 1.80MPa<P≤1.90MPa, 1.90MPa<P≤2.0MPa, P≥2.0MPa.

[0018] In some specific embodiments, during the blowing process, a reminder color is set at the intersection of the oxygen flow rate and the oxygen regulating valve opening coordinates to facilitate data modification.

[0019] In some specific embodiments, during the blowing process, a green background is provided at the intersection of the oxygen flow rate and the oxygen regulating valve opening coordinates to facilitate data modification.

[0020] The present application provides a method for stably controlling the oxygen pressure in a steelmaking process, which first formulates different static models according to converter working conditions, then sets different oxygen flow rates in the blowing stage, and establishes oxygen regulating valve opening data corresponding to the oxygen flow rates under different oxygen main pressures, and finally, when the working oxygen pressure and the target oxygen pressure are different, adjusts the oxygen regulating valve opening according to the oxygen regulating valve opening data so that the working oxygen pressure and the target oxygen pressure are the same; the present application establishes oxygen regulating valve opening data corresponding to the oxygen flow rate and the oxygen main pressure, and adjusts relevant factors according to the oxygen regulating valve data when the working oxygen pressure and the target oxygen pressure are different, thereby achieving consistency between the working oxygen pressure and the target oxygen pressure, thereby stably controlling the oxygen pressure; further, according to different oxygen main pressures, working oxygen pressures and oxygen flow rates, establishes one oxygen flow regulating valve opening value for each 0.05-0.10MPa fluctuation in the oxygen main pressure, thereby reducing the fluctuation in the oxygen flow regulating valve opening value and achieving stable control of the oxygen pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an oxygen pressure control curve diagram in the prior art of the present invention;

[0022] Figure 2 This is an oxygen pressure trend diagram after the oxygen pressure control method is stabilized according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0024] In view of the key role of oxygen supply pressure and oxygen flow rate in smelting in the prior art and the fluctuation problem of oxygen pressure during oxygen blowing, the present application provides a method for stably controlling oxygen pressure in the steelmaking process, which establishes a static model of converter steelmaking, explores the oxygen pressure regulating valve opening data corresponding to different oxygen flow rates under different oxygen main pressures, and automatically detects the oxygen main pressure, oxygen blowing steps and corresponding oxygen flow rates during the smelting process, and automatically adjusts the oxygen regulating valve opening in the primary computer, so as to stabilize the oxygen pressure used in the smelting process. Specifically, an embodiment of the present invention discloses a method for stably controlling oxygen pressure in the steelmaking process, comprising the following steps:

[0025] S1) formulating different static models according to converter operating conditions, wherein the static models are corresponding models of oxygen flow, distribution, gun position and oxygen pressure in different steelmaking stages;

[0026] S2) During the blowing stage, different oxygen flow rates are set;

[0027] Establish oxygen regulating valve opening data corresponding to oxygen flow rate under different oxygen main pipe pressures;

[0028] S3) When the used oxygen pressure is different from the target oxygen pressure, adjusting the oxygen regulating valve opening according to the oxygen regulating valve opening data to make the used oxygen pressure the same as the target oxygen pressure.

[0029] In the method provided in the present application, different static models are formulated according to the charge structure and molten iron conditions, wherein the static model is a control model of the oxygen flow rate, feed type, feed amount and gun position corresponding to different blowing oxygen steps; in this process, the charge structure and molten iron conditions, specifically, the molten iron conditions include low-temperature low-silicon, low-temperature high-silicon, high-temperature high-silicon, high-temperature low-silicon molten iron, etc., the charge structure is the amount of molten iron, the amount of scrap steel and the proportion of various types of scrap steel. According to the conditions of the molten iron entering the furnace, the computer automatically selects the corresponding static model, and the present application does not impose any special restrictions on this. In the static model, different oxygen flow rates are set during the blowing stage, and the corresponding settings of the charge, gun position and oxygen step are shown in Table 1, wherein the oxygen flow rate is set to a constant flow rate;

[0030] Table 1 Static model corresponding data table

[0031]

[0032]

[0033] In the above static model, according to the set value of oxygen flow in the static model parameters, a wider oxygen flow range is established, corresponding to the main pipe oxygen pressure and oxygen flow control valve data. Specifically, Q represents the oxygen flow in units of m 3 / h, the value range of the oxygen flow rate includes: Q≤3000, 3000<Q≤3100, 3100<Q≤3200, 3200<Q≤3300, 3300<Q≤3400, 3400<Q≤3500, 3500<Q≤3600, 3600<Q≤3700, 3700<Q≤3800, 3800<Q≤3900, 3900<Q≤4000; Correspondingly, the oxygen pressure range corresponding to each value range of the above oxygen flow rate includes: 0.0<P≤1.2MPa , 1.2MPa<P≤1.25MPa, 1.25MPa<P≤1.30MPa, 1.30MPa<P≤1.40MPa, 1.40MPa<P≤1.50MPa, 1.50MPa<P≤1.60MPa, 1.60MPa<P≤1.70MPa, 1.70MPa<P≤1.80MPa, 1.80MPa<P≤1.90MPa, 1.90MPa<P≤2.0MPa, P≥2.0MPa; For example, when the oxygen flow rate is Q≤3000m 3 / h, the corresponding oxygen pressure includes: 0.0<P≤1.2MPa, 1.2MPa<P≤1.25MPa, 1.25MPa<P≤1.30MPa, 1.30MPa<P≤1.40MPa, 1.40MPa<P≤1.50MPa, 1.50MPa<P≤1.60MPa, 1.60MPa<P≤1.70MPa, 1.70MPa<P≤1.80MPa, 1.80MPa<P≤1.90MPa , 1.90MPa<P≤2.0MPa, P≥2.0MPa, on the basis of this data, the oxygen flow rate adjustment opening data is determined, on the basis of other oxygen flow rate ranges, the corresponding oxygen pressure also includes the above range, thereby determining a series of oxygen flow rate and oxygen pressure corresponding to the oxygen flow rate opening data (the full opening is 100%, based on this, the opening data is the proportion data of the full opening); in different smelting stages, by adjusting the oxygen flow rate opening, it is ultimately ensured that the used oxygen pressure is the same as the target oxygen pressure.

[0034] In the smelting process, in order to facilitate the regulation of oxygen flow rate adjustment opening data, a reminder color is set at the coordinates corresponding to the set flow rate and the real-time main pipe oxygen pressure, more specifically a green background; for example, at a certain stage of blowing, the flow rate is set to 35000m 3 / h, at this time the oxygen main pipe pressure is 1.55Mpa. In the regulating valve opening table, the coordinate at the intersection of the set flow 35000 row and the main pipe pressure 1.50<P≤1.60 column turns "green".

[0035] In actual application, when the used oxygen pressure is different from the target oxygen pressure, the opening of the oxygen regulating valve is adjusted according to the oxygen regulating valve opening data to make the used oxygen pressure the same as the target oxygen pressure.

[0036] In the process of converter smelting, there is a nonlinear relationship between oxygen pressure and oxygen flow. When different oxygen main pressures need to achieve the same oxygen flow, the regulating valve opening data are not equal. When there is a deviation between the used oxygen flow and the set oxygen flow, the oxygen flow regulating valve is adjusted. When the deviation between the used oxygen flow and the set oxygen flow is large, the adjustment amplitude of the regulating valve is large, which is easy to over-adjust. When the deviation between the used oxygen flow and the set oxygen flow is small, the adjustment amplitude of the regulating valve is small, which is easy to under-adjust, and then the oxygen flow used fluctuates up and down. The present application achieves stable control of oxygen pressure by accurately corresponding to oxygen flow, oxygen pressure and oxygen flow regulating valve opening data, and using oxygen flow regulating valve opening data to accurately control the oxygen flow corresponding to different oxygen pressures; further, according to different oxygen main pressures, required oxygen pressure and oxygen flow, an oxygen flow regulating valve opening value is established for each fluctuation of 0.05-0.10Mpa in the oxygen main pressure, so as to reduce the large-scale regulation of the oxygen flow regulating valve and avoid large-scale fluctuations in oxygen flow.

[0037] In order to further understand the present invention, the method for stably controlling the oxygen pressure in the steelmaking process provided by the present invention is described in detail below in conjunction with embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0038] Example

[0039] A method for stably controlling oxygen pressure in an intelligent steelmaking process comprises the following steps:

[0040] 1) According to the charge structure and the steel type produced, different static models are formulated, which are the corresponding models of oxygen flow, charge distribution, gun position and oxygen pressure in different steelmaking stages;

[0041] 2) In different static models, different oxygen flow rates are set at different blowing stages;

[0042] 3) According to the maximum and minimum values ​​of oxygen flow rate set in the static model, establish the oxygen regulating valve opening table under different oxygen main pipe pressures;

[0043] 4) During the smelting process, the coordinates of the regulating valve opening corresponding to the oxygen flow rate and oxygen main pressure set in the static model will turn green, which is convenient for quick positioning when modifying data;

[0044] 5) During the smelting process, adjust the oxygen regulating valve opening data in the corresponding "coordinates" according to the usage;

[0045] 6) After all coordinates in the oxygen flow control valve opening table are summarized, it is put into use.

[0046] In the above step 2), the oxygen flow rate, material distribution and gun position control parameters of different static models in each smelting stage are shown in 2:

[0047] Table 2 Corresponding data table of relevant factors of static model

[0048] Oxygen Step <![CDATA[Oxygen flow rate, m 3 / h]]> Gun position, mm lime limestone Raw dolomite Dust ash pelletizing Bean Steel 2 33000 1700 4 33000 1700 6 33000 1600 8 33000 1600 60％ 100％ 10 33000 1550 90％ 100％ 15 33000 1500 60％ 22 33000 1450 10％ 28 33000 1400 40％ 33 33000 1350 38 33000 1350 45 33000 1350 50 33000 1350 56 33000 1350 10％ 62 33000 1350 10％ 70 33000 1350 10％ 76 33000 1350 10％ 80 33000 1400 86 33000 1450 100 33000 1250

[0049] In the above step 3), according to the oxygen flow setting value in the static model parameters, the oxygen flow, main pipe oxygen pressure and oxygen flow regulating valve opening table are established, as shown in Table 3:

[0050] Table 3 Oxygen flow rate, oxygen pressure and oxygen flow regulating valve opening (%)

[0051]

[0052] In the above step 4), in order to facilitate the modification of the regulating valve data during the smelting process, the coordinates corresponding to the set flow rate and the oxygen pressure of the main pipe at all times become "green background";

[0053] In the above step 5), during the smelting process, when the oxygen pressure is lower than the target value, the opening value in the corresponding coordinate is increased; when the oxygen pressure is higher than the target value, the opening value in the corresponding coordinate is decreased;

[0054] In the above step 6), according to the flow setting values ​​in different static models, the "coordinate" values ​​in the opening valve adjustment table are explored and perfected before being put into use.

[0055] Figure 1 It is the oxygen pressure control curve diagram in the prior art of the present invention, that is, before the voltage stabilization program is implemented, the oxygen pressure trend diagram used in the smelting process fluctuates frequently, the equipment control accuracy is poor, and it is not conducive to automatic steelmaking process control; Figure 2 This is the oxygen pressure trend diagram after the oxygen pressure control method is stabilized in the embodiment of the present invention. It can be seen from the figure that after the pressure stabilization method is used, the oxygen pressure trend diagram used in the smelting process is smoother, which improves the equipment control accuracy and enhances the effect of using the static model.

[0056] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for stably controlling oxygen pressure in a steelmaking process, comprising the following steps: S1) formulating different static models according to converter operating conditions, wherein the static models are corresponding models of oxygen flow, distribution, gun position and oxygen pressure in different steelmaking stages; S2) During the blowing stage, different oxygen flow rates are set; Establish oxygen regulating valve opening data corresponding to oxygen flow rate under different oxygen main pipe pressures; S3) When the used oxygen pressure is different from the target oxygen pressure, adjusting the oxygen regulating valve opening according to the oxygen regulating valve opening data to make the used oxygen pressure the same as the target oxygen pressure.

2. The method according to claim 1, characterized in that In step S1), the converter operating conditions include molten iron conditions, scrap steel structure and target steel grade.

3. The method according to claim 2, characterized in that The molten iron conditions include high-temperature high-silicon molten iron, low-temperature low-silicon molten iron, and low-temperature high-silicon molten iron.

4. The method according to claim 1, characterized in that In step S1), the range of the gun position is 1250-1700 mm.

5. The method according to claim 1, characterized in that In step S1), the gun positions are 1250mm, 1350mm, 1400mm, 1450mm, 1500mm, 1550mm, 1600mm, and 1700mm.

6. The method according to claim 1, characterized in that In step S1), the cloth material includes one or more of lime, limestone, raw dolomite, dust ash briquette and soybean steel.

7. The method according to claim 1, characterized in that In step S2), Q represents the oxygen flow rate, and the unit is m 3 / h, and the value range of the oxygen flow rate includes: Q≤3000, 3000<Q≤3100, 3100<Q≤3200, 3200<Q≤3300, 3300<Q≤3400, 3400<Q≤3500, 3500<Q≤3600, 3600<Q≤3700, 3700<Q≤3800, 3800<Q≤3900, 3900<Q≤4000.

8. The method according to claim 7, characterized in that The oxygen pressure range corresponding to each value interval of the oxygen flow rate includes: 0.0<P≤1.2MPa, 1.2MPa<P≤1.25MPa, 1.25MPa<P≤1.30MPa, 1.30MPa<P≤1.40MPa, 1.40MPa<P≤1.50MPa, 1.50MPa<P≤1.60MPa, 1.60MPa<P≤1.70MPa, 1.70MPa<P≤1.80MPa, 1.80MPa<P≤1.90MPa, 1.90MPa<P≤2.0MPa, P≥2.0MPa.

9. The method according to claim 1, characterized in that: During the blowing process, a reminder color is set at the intersection of the oxygen flow rate and the oxygen regulating valve opening coordinates to facilitate data modification.

10. The method according to claim 1 or 9, characterized in that: During the blowing process, a green background is set at the intersection of the oxygen flow rate and the oxygen regulating valve opening coordinates to facilitate data modification.

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