Dynamic control method, system and device for electric arc furnace steelmaking using direct reduced iron

Abstract

The present invention provides a dynamic control method, system and device for electric arc furnace steelmaking using direct reduced iron, belonging to the technical field of electric arc furnace steelmaking. The invention can well coordinate and match the smelting parameters in the process of electric arc furnace smelting hydrogen-based direct reduced iron, dynamically calculates through metallurgical models, uses a multi-objective decision-making method to determine the smelting parameters, and performs dynamic control output, so that the molten steel data conforms to the target data, and at the same time minimizes the energy consumption and carbon emissions of the smelting process, and has low cost, high efficiency, simple influencing factors, convenient operation and a wide range of applications, which is conducive to industrial production practice and promotion.

Description

Technical Field

[0001] The present invention relates to the technical field of electric arc furnace steelmaking, and in particular to a dynamic control method, system and device for electric arc furnace steelmaking using direct reduced iron. Background Art

[0002] Hydrogen-based direct reduced iron (hereinafter referred to as hydrogen-based direct reduced iron) is a metallic iron product that uses rich hydrogen / hydrogen gas as a reducing agent to reduce iron oxides in iron ore. It is one of the high-quality clean raw materials for electric arc furnace steelmaking. In the production process of electric arc furnaces, a certain proportion of hydrogen-based direct reduced iron is added with some scrap steel as raw materials for melting and smelting. However, due to the high gangue component, low carbon content, small particle size and density of hydrogen-based direct reduced iron, it is easy to float on the slag layer / slag steel interface during smelting, and has low thermal conductivity, resulting in slow melting speed and low melting efficiency. It is also greatly affected by the feeding speed. Too fast feeding speed will form an iceberg effect, and too slow feeding speed will lead to a long smelting cycle and high energy consumption.

[0003] The conventional smelting method is to increase the temperature of the raw materials entering the furnace and directly use hot direct reduced iron or preheat cold direct reduced iron for smelting; another feasible way is to use clustered oxygen supply, carbon powder blowing and other means to strengthen the blowing at the hydrogen-based direct reduced iron feeding port of the electric arc furnace to accelerate melting; in addition, the furnace wall burners can be added to the hydrogen-based direct reduced iron dropping area to increase energy input and promote rapid melting of direct reduced iron. However, the smelting process requires coordinated control of the feeding speed, power supply, oxygen supply, and carbon injection processes, and the thermal balance state in the furnace is unstable, which can easily lead to serious overoxidation of the molten steel, low metal recovery, high energy consumption, etc. At the same time, it will have a serious dependence on carbon powder, resulting in a large amount of CO2 emissions. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present invention provides a dynamic control method, system and device for electric arc furnace steelmaking using direct reduced iron. The invention can well coordinate and match the smelting parameters in the process of electric arc furnace smelting hydrogen-based direct reduced iron, dynamically calculate the metallurgical model, use a multi-objective decision-making method to determine the smelting parameters, and dynamically control the output, so that the molten steel data meets the target data, and at the same time minimize the energy consumption and carbon emissions of the smelting process. To achieve the above purpose, the technical scheme is as follows:

[0005] In a first aspect, the present invention provides a dynamic control method for steelmaking using direct reduced iron in an electric arc furnace, the method comprising:

[0006] S1, smelting starts, obtaining smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes target composition a1, target temperature a2, target weight a3, target basicity a4 and target slag system a5, the material composition data B includes metal material composition b1 and auxiliary material composition b2, and the equipment operation data C includes furnace body heat dissipation parameter c1, power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7;

[0007] S2, input the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption;

[0008] S3, according to the theoretical consumption and the power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 in the equipment operation data C, a multi-objective decision-making method is used to adjust the control gear to obtain the actual consumption;

[0009] S4, if the actual consumption is consistent with the theoretical consumption, execute S5; if the actual consumption is not consistent with the theoretical consumption, repeat S3;

[0010] S5. When the actual consumption meets the theoretical consumption, obtain the molten steel composition En and the molten steel temperature Tn. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, smelting ends. Otherwise, execute S6.

[0011] S6. Replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn. Repeat S2 to S5 until the smelting is completed.

[0012] Optionally, the theoretical consumption includes theoretical metal material weight Mn, theoretical gas consumption Gn, theoretical carbon consumption Kn, theoretical auxiliary material consumption Fn and theoretical power supply Pn.

[0013] Optionally, the metallurgical model includes a metallurgical material balance calculation method and a heat balance calculation method;

[0014] The metallurgical material balance calculation method is shown in formula (1):

[0015] (1)

[0016] In the formula, for the weight of each input material and target composition, The weight of each output material and target component;

[0017] The heat balance calculation method is shown in formula (2):

[0018] (2)

[0019] In the formula, is the heat released by the reaction of each material at the target temperature, It is the heat absorbed by each material reaction at the target temperature.

[0020] Optionally, the multi-objective decision-making method includes any one or more combinations of a linear weighted sum method, a hierarchical sequence method, a direct non-inferior solution method, a goal programming method, a hierarchical analysis method, a multi-objective group decision, and a fuzzy decision method.

[0021] Optionally, the judgment criterion for whether the actual consumption meets the theoretical consumption is that the actual consumption is 90% to 110% of the theoretical consumption.

[0022] Optionally, the electric arc furnace includes an ultra-high power electric arc furnace of 50-300t, a horizontal scrap steel preheating electric arc furnace, a stepped scrap steel preheating electric arc furnace, a vertical electric arc furnace and a double-shell electric arc furnace.

[0023] Optionally, the target component a1 includes the contents of carbon, silicon, manganese, phosphorus and sulfur in molten steel.

[0024] In a second aspect, the present invention provides a dynamic control system for electric arc furnace using direct reduced iron for steelmaking, the system is applied to a dynamic control method for electric arc furnace using direct reduced iron for steelmaking, the system comprising:

[0025] The first acquisition module is used to acquire the smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes the target composition a1, the target temperature a2, the target weight a3, the target basicity a4 and the target slag system a5, the material composition data B includes the metal material composition b1 and the auxiliary material composition b2, and the equipment operation data C includes the furnace body heat dissipation parameter c1, the power supply gear control parameter c2, the oxygen supply gear control parameter c3, the gas gear control parameter c4, the carbon injection gear control parameter c5, the metal material feeding control parameter c6 and the auxiliary material feeding control parameter c7;

[0026] Theoretical calculation module, used for inputting the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption;

[0027] The second acquisition module is used to obtain the actual consumption after adjusting the control gear according to the theoretical consumption and the power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 in the equipment operation data C by adopting a multi-objective decision-making method;

[0028] A first judgment module, configured to proceed to the next step if the actual consumption is consistent with the theoretical consumption, and repeat the previous step if the actual consumption is inconsistent with the theoretical consumption;

[0029] The second judgment module is used to obtain the molten steel composition En and the molten steel temperature Tn when the actual consumption meets the theoretical consumption. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is ended, otherwise, the next step is performed;

[0030] The data replacement module is used to replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn, and repeat S2 to S5 until the smelting is completed.

[0031] In the third aspect, the present invention provides a dynamic control device for an electric arc furnace using direct reduced iron to make steel, the device is applied to a dynamic control method for an electric arc furnace using direct reduced iron to make steel and a dynamic control system for an electric arc furnace using direct reduced iron to make steel, the device includes a metal material feeding system, a computer control system, a powder spraying system, a smelting system and a gas source, the dynamic control device for an electric arc furnace using direct reduced iron to make steel implements the steps in the dynamic control method for an electric arc furnace using direct reduced iron to make steel.

[0032] Optionally, the metal material feeding system includes a direct reduced iron silo, a metal material silo, a chain conveyor, a conveying device, a conveying channel and hydrogen-based direct reduced iron;

[0033] The computer control system includes a computer, a PLC control cabinet, cables and a hub;

[0034] The powder spraying system comprises a carbon powder spraying tank, an auxiliary material spraying tank, a carbon powder control valve group and an auxiliary material control valve group;

[0035] The smelting system includes an electric arc furnace, electrodes, auxiliary material spray guns, carbon powder spray guns, gas guns, oxygen guns and bottom blowing elements;

[0036] The gas source includes a gas storage tank, a gas control valve group, a gas pipeline valve group 1 and a gas pipeline valve group 2.

[0037] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0038] On the one hand, the above scheme can well coordinate and match the charging tasks in the process of hydrogen-based direct reduction of electric arc furnace smelting. Through dynamic calculation of metallurgical model, the material consumption is determined by multi-objective decision-making method, and dynamic control output is performed to make the molten steel data meet the target data. On the other hand, the smelting process has the lowest energy consumption and carbon emissions, and it has low cost, high efficiency, simple influencing factors, convenient operation and wide application range, which is conducive to industrial production practice and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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 creative work.

[0040] Figure 1 is a flowchart of steps of an embodiment of a dynamic control method for electric arc furnace steelmaking using direct reduced iron according to the present invention;

[0041] Figure 2 It is a schematic block diagram of the steps of an embodiment of a dynamic control method for electric arc furnace steelmaking using direct reduced iron according to the present invention;

[0042] Figure 3 is a system block diagram of an embodiment of a dynamic control system for electric arc furnace steelmaking using direct reduced iron according to the present invention;

[0043] Figure 4 It is a schematic diagram of an embodiment of a dynamic control device for electric arc furnace steelmaking using direct reduced iron according to the present invention.

[0044] Explanation of the numbers in the figure: direct reduced iron silo 1-1, conveying device 1-2, hydrogen-based direct reduced iron 1-3, conveying channel 1-4, metal material silo 1-5, chain conveyor 1-6, computer 2-1, PLC control cabinet 2-2, cable 2-3, hub 2-4, carbon powder spray tank 3-1, auxiliary material spray tank 3-2, carbon powder control valve group 3-3, auxiliary material control valve group 3-4, gas storage tank 4-1, gas control valve group 4-2, gas pipeline valve group 1 4-3, gas pipeline valve group 2 4-4, electric arc furnace 5-1, electrode 5-2, carbon powder spray gun 5-3, auxiliary material spray gun 5-4, gas gun 5-5, bottom blowing element 5-6, oxygen gun 5-7. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0046] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0047] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0048] Embodiment 1:

[0049] This embodiment 1 can be applied to a 120t CONSTEEL electric arc furnace for smelting low-carbon steel, using 50% hydrogen-based direct reduced iron and 50% scrap steel as smelting raw materials.

[0050] like Figure 1 The step flow chart of an embodiment of a dynamic control method for making steel using direct reduced iron in an electric arc furnace is shown in FIG. Figure 2 The present invention provides a dynamic control method for steelmaking using direct reduced iron in an electric arc furnace, which is implemented by a dynamic control system for steelmaking using direct reduced iron in an electric arc furnace and a dynamic control device for steelmaking using direct reduced iron in an electric arc furnace. The method comprises:

[0051] S1, smelting starts, obtaining smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes target composition a1, target temperature a2, target weight a3, target basicity a4 and target slag system a5, the material composition data B includes metal material composition b1 and auxiliary material composition b2, and the equipment operation data C includes furnace body heat dissipation parameter c1, power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7;

[0052] Specifically, at the beginning of smelting, the carbon content of target component a1 is 0.1%, the silicon content is 0.05%, the manganese content is 0.15%, the phosphorus content is 0.09%, and the sulfur content is 0.07%. The target temperature a2 is 1620°C, the target weight a3 is 120t, the target basicity a4 is 2.5, and the target slag system a5 has a main component of calcium oxide content of 88%, silicon dioxide content of 2.5%, magnesium oxide content of 2.6%, and aluminum oxide content of 1.5%; the main component of metal component b1 is calcium oxide content of 49.6%, silicon dioxide content of 1.6%, magnesium oxide content of 31.9%, and aluminum oxide content of 3%; the main component of auxiliary component b2 is carbon content of 75%, and the sulfur content does not exceed 0.05%; the cooling water flow rate of furnace heat dissipation parameter c1 in equipment operation data C is 4500m 3 / t, the power supply gear in the oxygen supply gear control parameter c3 is set to 1~22, the oxygen supply gear in the oxygen supply gear control parameter c3 is set to 1~5, the biomass gas injection gear is 1-5, the carbon injection gear control parameter c5 is set to 1~5, the feeding speed of scrap steel and hydrogen-based direct reduction iron in the metal material feeding control parameter c6 is set to 0~8t / min, and the auxiliary material powder injection speed in the auxiliary material feeding control parameter c7 is ≤120kg / min.

[0053] S2, input the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption;

[0054] Specifically, the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C are input into the metallurgical model, and the metallurgical material balance calculation method and the heat balance calculation method are used;

[0055] The metallurgical material balance calculation method is shown in formula (1):

[0056] (1)

[0057] In the formula, for the weight of each input material and target composition, The weight of each output material and target component;

[0058] The heat balance calculation method is shown in formula (2):

[0059] (2)

[0060] In the formula, is the heat released by the reaction of each material at the target temperature, It is the heat absorbed by each material reaction at the target temperature.

[0061] These two balance calculation methods are commonly used in the prior art for the calculation of conservation of matter and energy. The embodiments of the present invention are not described in detail here. The theoretical metal material weight Mn contains 65t of scrap steel and 65t of hydrogen-based direct reduction iron, and the theoretical gas consumption Gn contains 6255Nm of oxygen. 3 and biomass gas is 350Nm 3 The theoretical carbon consumption Kn is 1100kg of biochar powder, the theoretical auxiliary material consumption Fn is 3750kg of lime and 2100kg of dolomite, and the theoretical power supply Pn is 47100kW·h.

[0062] S3, according to the theoretical consumption, the actual consumption and the power supply gear control parameter c2, the oxygen supply gear control parameter c3, the gas gear control parameter c4, the carbon injection gear control parameter c5, the metal material feeding control parameter c6 and the auxiliary material feeding control parameter c7 in the equipment operation data C, a multi-objective decision method is used to adjust the control gear to obtain the actual consumption;

[0063] Specifically, according to the theoretical consumption, the smelting process is divided into 10 stages, each stage lasting 3 minutes, including the startup period, initial charging period, charging period 1, charging period 2, charging period 3, charging period 4, charging period 5, slag making period, melting period and heating period. The target programming method is used to determine the distribution of electricity, oxygen, biomass gas, biochar powder, scrap steel, hydrogen-based direct reduction iron, lime and dolomite in each stage, see Table 1.

[0064] Table 1-Phase planning operation table of Example 1

[0065]

[0066] According to the power supply gear control parameter c2 (as shown in Table 2), oxygen supply gear control parameter c3 (as shown in Table 3), gas gear control parameter c4 (as shown in Table 4, biomass gas), carbon injection gear control parameter c5 (as shown in Table 4, oxygen), metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 (as shown in Table 5) in the planned operations of each stage and the equipment operation data C obtained in Table 1, the power supply gear, oxygen supply gear, biomass gas gear, biochar powder injection gear, scrap steel and hydrogen-based direct reduction iron feeding speed, lime and dolomite powder injection speed are adjusted respectively, and the consumption data during the startup period are collected to obtain the actual consumption.

[0067] Table 2-Power supply gear control parameter table of Example 1

[0068]

[0069] Table 3 - Oxygen supply and biomass gas gear control parameter table of Example 1

[0070]

[0071] Table 4- Carbon injection gear control parameter table of Example 1

[0072]

[0073] Table 5 - Table of control parameters of auxiliary material addition in Example 1

[0074]

[0075] S4. If the actual consumption is consistent with the theoretical consumption, execute S5. If the actual consumption is not consistent with the theoretical consumption, repeat S3.

[0076] S5. When the actual consumption meets the theoretical consumption, the molten steel composition En and the molten steel temperature Tn are obtained. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is ended, otherwise, the next step is performed;

[0077] Specifically, when the consumption of electricity, oxygen, biochar, biomass gas, lime powder, dolomite powder, scrap steel and hydrogen-based direct reduction iron reaches 90% of the planned consumption respectively, the molten steel temperature Tn and the molten steel composition En are collected. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is ended, otherwise S6 is executed.

[0078] S6. Replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn. Repeat S2 to S5 until the smelting is completed.

[0079] Embodiment 2:

[0080] This embodiment 2 can be applied to a 60t ultra-high power electric arc furnace for smelting ultra-low carbon steel, using 30% hydrogen-based direct reduced iron and 70% scrap steel as smelting raw materials.

[0081] like Figure 1 to Figure 2 As shown, the present invention provides a dynamic control method for electric arc furnace using direct reduced iron for steelmaking, the method is implemented by a dynamic control system for electric arc furnace using direct reduced iron for steelmaking and a dynamic control device for electric arc furnace using direct reduced iron for steelmaking, the method comprising:

[0082] S1, smelting starts, obtaining smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes target composition a1, target temperature a2, target weight a3, target basicity a4 and target slag system a5, the material composition data B includes metal material composition b1 and auxiliary material composition b2, and the equipment operation data C includes furnace body heat dissipation parameter c1, power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7;

[0083] Specifically, at the beginning of smelting, the carbon content of target component a1 is 0.03%, the silicon content is 0.05%, the manganese content is 0.1%, the phosphorus content is 0.06%, and the sulfur content is 0.06%. The target temperature a2 is 1620°C, the target weight a3 is 60t, the target basicity a4 is 2.8, and the main components of target slag system a5 are calcium oxide content of 88%, silicon dioxide content of 2.5%, magnesium oxide content of 2.6%, and aluminum oxide content of 1.5%; the main components of metal material component b1 are calcium oxide content of 49.6%, silicon dioxide content of 1.6%, magnesium oxide content of 31.9%, and aluminum oxide content of 3%; the main component of auxiliary material component b2 is carbon content of 75%, and the sulfur content does not exceed 0.05%; the cooling water flow rate of furnace heat dissipation parameter c1 in equipment operation data C is 3000m 3 / t, the power supply gear in the oxygen supply gear control parameter c3 is set to 1~22, the oxygen supply gear in the oxygen supply gear control parameter c3 is set to 1~5, the biomass gas injection gear is 1-5, the carbon injection gear control parameter c5 is set to 1~5, the feeding speed of scrap steel and hydrogen-based direct reduction iron in the metal material feeding control parameter c6 is set to 0~8t / min, and the auxiliary material powder injection speed in the auxiliary material feeding control parameter c7 is ≤100kg / min.

[0084] S2, input the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption;

[0085] Specifically, the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C are input into the metallurgical model, and the metallurgical material balance calculation method and the heat balance calculation method are used;

[0086] The metallurgical material balance calculation method is shown in formula (3):

[0087] (3)

[0088] In the formula, for the weight of each input material and target composition, The weight of each output material and target component;

[0089] The heat balance calculation method is shown in formula (4):

[0090] (4)

[0091] In the formula, is the heat released by the reaction of each material at the target temperature, It is the heat absorbed by each material reaction at the target temperature.

[0092] These two balance calculation methods are commonly used in the prior art for the calculation of conservation of matter and energy. The embodiments of the present invention are not described in detail here. The theoretical metal material weight Mn includes 45t of scrap steel and 20t of hydrogen-based direct reduction iron, and the theoretical gas consumption Gn is 3270Nm 3 , the theoretical carbon consumption Kn is 450kg of biochar powder, the theoretical auxiliary material consumption Fn is 1500kg of lime, and the theoretical power supply Pn is 19400kW·h.

[0093] S3, according to the theoretical consumption, the actual consumption and the power supply gear control parameter c2, the oxygen supply gear control parameter c3, the gas gear control parameter c4, the carbon injection gear control parameter c5, the metal material feeding control parameter c6 and the auxiliary material feeding control parameter c7 in the equipment operation data C, a multi-objective decision method is used to adjust the control gear to obtain the actual consumption;

[0094] Specifically, according to the theoretical consumption, the smelting process is divided into 7 stages, each stage lasting 5 minutes, including the startup period, scrap steel feeding period 1, scrap steel feeding period 2, hydrogen-based direct reduction iron feeding period, slag making period, melting period and heating period. The multi-objective group decision-making method is used to determine the distribution of electricity, oxygen, biochar powder, scrap steel, hydrogen-based direct reduction iron and lime in each stage, see Table 1.

[0095] Table 6-Phase planning operation table of Example 2

[0096]

[0097] According to the power supply gear control parameter c2 (as shown in Table 7), oxygen supply gear control parameter c3 (as shown in Table 8), carbon injection gear control parameter c5 (as shown in Table 9), metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 (as shown in Table 10) in the planned operations of each stage and the equipment operation data C obtained in Table 6, the power supply gear, oxygen supply gear, biochar powder injection gear, scrap steel and hydrogen-based direct reduction iron feeding speed, lime powder injection speed are adjusted respectively, and the consumption data during the startup period are collected to obtain the actual consumption.

[0098] Table 7-Power supply gear control parameter table of Example 2

[0099]

[0100] Table 8 - Oxygen supply gear control parameter table of Example 2

[0101]

[0102] Table 9- Carbon injection gear control parameter table of Example 2

[0103]

[0104] Table 10 - Table of control parameters of auxiliary material addition in Example 2

[0105]

[0106] S4. If the actual consumption is consistent with the theoretical consumption, execute S5. If the actual consumption is not consistent with the theoretical consumption, repeat S3.

[0107] S5. When the actual consumption meets the theoretical consumption, obtain the molten steel composition En and the molten steel temperature Tn. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is terminated. Otherwise, execute S6.

[0108] Specifically, when the consumption of electricity, oxygen, biochar, biomass gas, lime powder, dolomite powder, scrap steel and hydrogen-based direct reduction iron addition reaches 100% of the planned consumption respectively, the molten steel temperature Tn and the molten steel composition En are collected. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is completed, otherwise proceed to the next step.

[0109] S6. Replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn. Repeat S2 to S5 until the smelting is completed.

[0110] like Figure 3 As shown, the present invention provides a dynamic control system for electric arc furnace using direct reduced iron for steelmaking, the system is applied to a dynamic control method for electric arc furnace using direct reduced iron for steelmaking, the system comprises: a first acquisition module, a theoretical calculation module, a second acquisition module, a first judgment module, a second judgment module and a data replacement module, specifically,

[0111] The first acquisition module is used to acquire the smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes the target composition a1, the target temperature a2, the target weight a3, the target basicity a4 and the target slag system a5, the material composition data B includes the metal material composition b1 and the auxiliary material composition b2, and the equipment operation data C includes the furnace body heat dissipation parameter c1, the power supply gear control parameter c2, the oxygen supply gear control parameter c3, the gas gear control parameter c4, the carbon injection gear control parameter c5, the metal material feeding control parameter c6 and the auxiliary material feeding control parameter c7;

[0112] Theoretical calculation module, used for inputting the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption;

[0113] The second acquisition module is used to obtain the actual consumption after adjusting the control gear according to the theoretical consumption and the power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 in the equipment operation data C by adopting a multi-objective decision-making method;

[0114] A first judgment module, configured to proceed to the next step if the actual consumption is consistent with the theoretical consumption, and repeat the previous step if the actual consumption is inconsistent with the theoretical consumption;

[0115] The second judgment module is used to obtain the molten steel composition En and the molten steel temperature Tn when the actual consumption meets the theoretical consumption. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is ended, otherwise, the next step is performed;

[0116] The data replacement module is used to replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn, and repeat S2 to S5 until the smelting is completed.

[0117] like Figure 4 As shown, the present invention provides a dynamic control device for electric arc furnace using direct reduced iron for steelmaking, the device is applied to a dynamic control method for electric arc furnace using direct reduced iron for steelmaking and a dynamic control system for electric arc furnace using direct reduced iron for steelmaking, the device includes a metal material feeding system, a computer control system, a powder spraying system, a smelting system and a gas source, the dynamic control device for electric arc furnace using direct reduced iron for steelmaking implements the steps of the dynamic control method for electric arc furnace using direct reduced iron for steelmaking.

[0118] Specifically, the metal material feeding system includes a direct reduced iron silo 1-1, a metal material silo 1-5, a chain conveyor 1-6, a conveying device 1-2, a conveying channel 1-4 and a hydrogen-based direct reduced iron 1-3;

[0119] The computer control system includes a computer 2-1, a PLC control cabinet 2-2, a cable 2-3 and a hub 2-4;

[0120] The powder spraying system includes a carbon powder spray tank 3-1, an auxiliary material spray tank 3-2, a carbon powder control valve group 3-3 and an auxiliary material control valve group 3-4;

[0121] The smelting system includes an electric arc furnace 5-1, an electrode 5-2, an auxiliary material spray gun 5-4, a carbon powder spray gun 5-3, a gas gun 5-5, an oxygen gun 5-7 and a bottom blowing element 5-6;

[0122] The gas source includes a gas storage tank 4-1, a gas control valve group 4-2, a gas pipeline valve group 1 4-3 and a gas pipeline valve group 2 4-4.

[0123] The present invention provides a dynamic control method and device for steelmaking using direct reduced iron in an electric arc furnace. The invention can coordinate and match the smelting parameters in the process of smelting hydrogen-based direct reduced iron in an electric arc furnace well. Through dynamic calculation of a metallurgical model, the smelting parameters are determined using a multi-objective decision-making method, and dynamic control output is performed to make the molten steel data conform to the target data. At the same time, the smelting process consumes the least energy and has the lowest carbon emissions. In addition, the invention has low cost, high efficiency, simple influencing factors, convenient operation and a wide range of applications, which is conducive to industrial production practice and promotion.

[0124] It is to be understood that the present invention is described by the above embodiments and should not be construed as limiting the embodiments of the present invention and the scope of the present invention. It is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A dynamic control method for electric arc furnace steelmaking using direct reduced iron, characterized in that: The method comprises: S1, smelting starts, obtaining smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes target composition a1, target temperature a2, target weight a3, target basicity a4 and target slag system a5, the material composition data B includes metal material composition b1 and auxiliary material composition b2, and the equipment operation data C includes furnace body heat dissipation parameter c1, power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7; S2, input the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption; S3, according to the theoretical consumption and the power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 in the equipment operation data C, a multi-objective decision-making method is used to adjust the control gear to obtain the actual consumption; S4, if the actual consumption is consistent with the theoretical consumption, execute S5; if the actual consumption is not consistent with the theoretical consumption, repeat S3; S5. When the actual consumption meets the theoretical consumption, obtain the molten steel composition En and the molten steel temperature Tn. If the molten steel composition En meets the target composition a1 in the smelting plan data A, and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, then smelting ends. Otherwise, execute S6. S6. Replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn. Repeat S2 to S5 until the smelting is completed.

2. The dynamic control method for steelmaking using direct reduced iron in an electric arc furnace according to claim 1, characterized in that: The theoretical consumption includes theoretical metal material weight Mn, theoretical gas consumption Gn, theoretical carbon consumption Kn, theoretical auxiliary material consumption Fn and theoretical power supply Pn.

3. The dynamic control method for steelmaking using direct reduced iron in an electric arc furnace according to claim 1, characterized in that: The metallurgical model includes a metallurgical material balance calculation method and a heat balance calculation method; The metallurgical material balance calculation method is shown in formula (1): （1） In the formula, for the weight of each input material and target composition, The weight of each output material and target component; The heat balance calculation method is shown in formula (2): （2） In the formula, is the heat released by the reaction of each material at the target temperature, It is the heat absorbed by each material reaction at the target temperature.

4. The dynamic control method for steelmaking using direct reduced iron in an electric arc furnace according to claim 1, characterized in that: The multi-objective decision-making method includes any one or more combination methods of linear weighted sum method, hierarchical sequence method, direct non-inferior solution method, target programming method, hierarchical analysis method, multi-objective group decision-making, and fuzzy decision-making.

5. The dynamic control method for steelmaking using direct reduced iron in an electric arc furnace according to claim 1, characterized in that: The judgment standard that the actual consumption meets the theoretical consumption is: the actual consumption is 90% to 110% of the theoretical consumption.

6. The dynamic control method for electric arc furnace steelmaking using direct reduced iron according to claim 1, characterized in that: The electric arc furnace includes an ultra-high power electric arc furnace of 50-300t, a horizontal scrap steel preheating electric arc furnace, a stepped scrap steel preheating electric arc furnace, a vertical electric arc furnace and a double-shell electric arc furnace.

7. The dynamic control method for electric arc furnace steelmaking using direct reduced iron according to claim 1, characterized in that: The target composition a1 includes the contents of carbon, silicon, manganese, phosphorus and sulfur in molten steel.

8. A dynamic control system for electric arc furnace steelmaking using direct reduced iron, characterized in that: The system comprises: The first acquisition module is used to acquire the smelting plan data A, material composition data B and equipment operation data C of the electric arc furnace, wherein the smelting plan data A includes the target composition a1, the target temperature a2, the target weight a3, the target basicity a4 and the target slag system a5, the material composition data B includes the metal material composition b1 and the auxiliary material composition b2, and the equipment operation data C includes the furnace body heat dissipation parameter c1, the power supply gear control parameter c2, the oxygen supply gear control parameter c3, the gas gear control parameter c4, the carbon injection gear control parameter c5, the metal material feeding control parameter c6 and the auxiliary material feeding control parameter c7; Theoretical calculation module, used for inputting the target composition a1, target temperature a2, target weight a3, target basicity a4, target slag system a5 in the smelting plan data A, the metal material composition b1, auxiliary material composition b2 in the material composition data B and the furnace heat dissipation parameter c1 in the equipment operation data C into the metallurgical model to obtain the theoretical consumption; The second acquisition module is used to obtain the actual consumption after adjusting the control gear according to the theoretical consumption and the power supply gear control parameter c2, oxygen supply gear control parameter c3, gas gear control parameter c4, carbon injection gear control parameter c5, metal material feeding control parameter c6 and auxiliary material feeding control parameter c7 in the equipment operation data C by adopting a multi-objective decision-making method; A first judgment module, configured to proceed to the next step if the actual consumption is consistent with the theoretical consumption, and repeat the previous step if the actual consumption is inconsistent with the theoretical consumption; The second judgment module is used to obtain the molten steel composition En and the molten steel temperature Tn when the actual consumption meets the theoretical consumption. If the molten steel composition En meets the target composition a1 in the smelting plan data A and the molten steel temperature Tn meets the target temperature a2 in the smelting plan data A, the smelting is ended, otherwise, the next step is performed; The data replacement module is used to replace the target component a1 in the smelting plan data A with the molten steel component En, and replace the target temperature a2 in the smelting plan data A with the molten steel temperature Tn, and repeat S2 to S5 until the smelting is completed.

9. A dynamic control device for electric arc furnace steelmaking using direct reduced iron, characterized in that: The device includes a metal material feeding system, a computer control system, a powder spraying system, a smelting system and a gas source. The dynamic control device for electric arc furnace using direct reduced iron for steelmaking implements the steps in the dynamic control method for electric arc furnace using direct reduced iron for steelmaking as claimed in any one of claims 1-7.

10. The dynamic control device for electric arc furnace steelmaking using direct reduced iron according to claim 9, characterized in that: The metal material feeding system comprises a direct reduced iron silo, a metal material silo, a chain conveyor, a conveying device, a conveying channel and hydrogen-based direct reduced iron; The computer control system includes a computer, a PLC control cabinet, cables and a hub; The powder spraying system comprises a carbon powder spraying tank, an auxiliary material spraying tank, a carbon powder control valve group and an auxiliary material control valve group; The smelting system includes an electric arc furnace, electrodes, auxiliary material spray guns, carbon powder spray guns, gas guns, oxygen guns and bottom blowing elements; The gas source includes a gas storage tank, a gas control valve group, a gas pipeline valve group 1 and a gas pipeline valve group 2.

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