Calculation method for determining economic oxygen enrichment rate of blast furnace based on constant thermal parameters

Abstract

The invention provides a calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, and relates to the technical field of ferrous metallurgy. The method aims at solving the technical problem that the economic oxygen enrichment rate capable of guaranteeing the stability of the thermal regulation cannot be cooperatively determined when the proportion of the bituminous coal injected by the blast furnace is adjusted. The method comprises the following steps: determining a theoretical combustion temperature and a blast furnace heat loss value under a reference working condition as target constraint conditions; for different coal price differences and bituminous coal mixing proportions, performing iterative calculation by cooperatively adjusting the oxygen enrichment rate and the total coal injection ratio so as to solve operation parameters meeting the constraint conditions; and then the smelting cost per ton of iron under each working condition is calculated, and the oxygen enrichment rate corresponding to the lowest point of the cost is determined through optimization, namely the economic oxygen enrichment rate. The method can actively adapt to market price fluctuation, provides a scientific and quantitative decision basis for low-cost operation on the premise of guaranteeing stable operation of the blast furnace, and effectively improves the economic benefits of the blast furnace.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and more specifically, to a method for cost optimization and control in blast furnace ironmaking, particularly a method for determining the economic oxygen enrichment rate by changing the proportion of injected bituminous coal while keeping thermal parameters constant. Background Technology

[0002] In blast furnace ironmaking, pulverized coal injection is a key technological approach to replace some coke and achieve energy conservation and cost reduction. Tuyere pulverized coal injection and oxygen-enriched blast are two key modern technologies that are of great significance for optimizing key technical and economic indicators of the blast furnace, such as reducing the coke ratio, increasing output, and stabilizing furnace conditions. In production practice, in order to effectively control fuel costs, which account for a very high proportion of the cost per ton of iron, it is common practice to mix bituminous coal and anthracite for injection, which are relatively inexpensive. The mixing ratio of the two is adjusted according to market dynamics, such as price differences, which is a routine cost reduction measure.

[0003] Patent application CN118822589A discloses a method for calculating the economical blending of pulverized coal for blast furnace injection. The method includes: establishing a pulverized coal composition analysis database based on the composition analysis of individual coal types and blended coals; determining the cost-effectiveness of each coal type through process calculations based on the database; and adjusting the pulverized coal structure and calculating costs based on this cost-effectiveness to determine the economical blending scheme that meets the quality requirements of pulverized coal for blast furnace injection and has the optimal cost. This scheme provides a systematic method for optimizing the economical blending ratio of pulverized coal from the perspective of raw materials and fuels.

[0004] However, this scheme primarily focuses on optimizing the pulverized coal blending ratio itself. That is, how to blend a coal powder mixture with the highest cost-effectiveness among various coal types. After determining the economical coal blending ratio, it fails to provide a method for collaboratively determining the oxygen enrichment rate that dynamically matches this ratio.

[0005] In actual blast furnace production, changes in the proportion of bituminous coal directly affect the combustion process inside the furnace. If operating parameters such as oxygen enrichment rate are not adjusted in a coordinated manner, it is easy to cause deviations in the core thermal state of the blast furnace, especially fluctuations in the theoretical combustion temperature.

[0006] Theoretical combustion temperature is a core indicator characterizing the heat supply intensity of the lower part of the blast furnace. A stable theoretical combustion temperature can ensure the long-term stable operation of the blast furnace. Therefore, simply determining an economical pulverized coal ratio without providing matching operating parameters that can guarantee stable production may not be fully economical in practical applications.

[0007] In summary, a technical problem still exists in this field: how to find an economic oxygen enrichment rate that can maintain the stability of the core thermal system while adjusting the bituminous coal injection ratio to reduce costs, and ensure that the economic oxygen enrichment rate can minimize the overall smelting cost under the premise of stable operation. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters. This method aims to solve the technical problem that existing technologies, when optimizing the pulverized coal ratio for blast furnaces, fail to provide a coordinated method for determining the oxygen enrichment rate that can ensure the constancy of the core thermal regime of the blast furnace.

[0009] This invention can reduce costs by changing the ratio of bituminous coal injection, while maintaining stable production and achieving the lowest economic oxygen enrichment rate for overall smelting costs.

[0010] To achieve the above objectives, this invention provides a method for calculating the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, comprising the following steps: S1, determine the baseline working conditions and target constraints; Select a baseline operating condition, such as the full anthracite injection condition, obtain its production data, and determine a baseline theoretical combustion temperature through calculation using a blast furnace heat balance model. A benchmark blast furnace heat loss value .Should and These will be set as target constraints that must be satisfied in subsequent calculations.

[0011] S2, set the gradients for economic and process variables; Set the price difference between bituminous coal and anthracite ( ΔP ) as an economic variable, and take values ​​according to a certain gradient (e.g., ΔP =0.2, 0.175, 0.15… yuan / kg); at the same time, the mixing ratio of bituminous coal in the total pulverized coal injection is set ( x %) is used as a process variable and takes values ​​according to a certain gradient (e.g., x = 10%, 20%, 30%...).

[0012] S3 performs optimization calculations under constraints; For each price difference set in step S2 ( ΔP ) and the blending ratio of each bituminous coal ( x %), as determined in step S1 and To constrain the process, iterative calculations are performed by coordinating the oxygen enrichment rate (ER) and the coal content ratio (PCI) until a specific set of solutions (ER, PCI) that simultaneously satisfies the constraints is found. This process aims to solve the following system of equations: In the formula, The theoretical combustion temperature is a function that can be determined using the following heat balance formula for the air vent swirl zone: In the formula: —Heat release from coke combustion at the tuyere, kJ / tHM; —Heat release from fuel combustion (kJ / tHM); —The sensible heat brought in by the coke, kJ / tHM; —Heat carried in by circulating gas, kJ / tHM; —The reaction of moisture in fuel and blower air consumes heat, kJ / tHM; —Desorption heat of pulverized coal volatilization and decomposition, kJ / tHM; —Heat consumption for methane decomposition in circulating gas, kJ / tHM; —Slag formation heat, kJ / tHM, —Average heat capacity of gas in the tuyeres' vortex zone, kJ / (℃·m³) 3 ); —Gas volume in the vent swirl zone, m 3 / tHM; —Average heat capacity of fuel ash, kJ / (℃·kg); —Fuel ash content, kg / tHM; —Average heat capacity of unburned pulverized coal, kJ / (℃·kg); —Quantity of unburned pulverized coal, kJ / tHM; This is the blast furnace heat loss function, and its value is determined through full blast furnace heat balance calculation.

[0013] Specifically, the calculation includes: a) Calculate the total heat revenue of the blast furnace ( This mainly includes the physical heat of the blower and the heat of fuel combustion; b) Calculate the main heat expenditure items other than furnace body heat dissipation, mainly including the physical heat carried away by molten iron and slag ( ), physical and chemical heat carried away by the gas at the top of the furnace ( ), and the net endothermic reaction of each chemical reaction ( )wait; Blast furnace heat loss ( That is, the total heat revenue minus the above-mentioned major heat expenditure items is obtained: In iterative calculations, changes in oxygen enrichment rate (ER) and coal ratio (PCI) will affect total heat revenue and various heat expenditures, thus jointly determining... The final calculation result.

[0014] S4, calculate the cost of smelting one ton of iron under various working conditions; For each specific solution that satisfies the conditions obtained in step S3, combined with the corresponding price difference in step S2, and other preset raw material and fuel costs and by-product revenues, calculate the cost per ton of iron fuel under this operating condition. ), cost of smelting one ton of iron ( ).

[0015] The fuel and smelting cost per ton of iron can be calculated using the following formula: In the formula, The cost of smelting iron is expressed in yuan / ton. The cost of fuel per ton of iron is yuan / ton; Cost per ton of iron ore, in yuan / ton; The cost of coke is per ton of iron, expressed in yuan / ton. The cost per ton of iron ore pulverized coal related to the price difference, in yuan / ton; The cost of oxygen production per ton of iron is yuan / ton; The profit per ton of iron slag is RMB / ton; The revenue per ton of iron ore gas is yuan / ton.

[0016] S5, determine the economic oxygen enrichment rate and establish a decision-making model; For each price difference ( ΔP The cost per ton of iron is compared across all bituminous coal blending ratios to determine the lowest cost point. If a lowest point exists, the oxygen enrichment rate (ER) corresponding to that point is the economic oxygen enrichment rate for that price difference. This process is repeated to obtain the economic oxygen enrichment rate for all price differences, and the results can be generated as a data lookup table or a 3D decision model diagram to visually represent the relationship between price differences, bituminous coal ratios, and cost per ton of iron.

[0017] Furthermore, the by-product revenue refers to the revenue from coal gas and blast furnace slag resulting from changes in the coal ratio and oxygen enrichment rate.

[0018] Furthermore, the benchmark operating condition is the condition of full anthracite injection.

[0019] Furthermore, in step S1, the reference theoretical combustion temperature and benchmark blast furnace heat loss value It is obtained by performing material balance and heat balance calculations on the aforementioned benchmark operating conditions.

[0020] Furthermore, in step S3, the iterative calculation is performed based on the blast furnace heat balance model to ensure that the calculation results meet the target constraints.

[0021] Furthermore, in step S4, the calculation of the cost per ton of iron smelting comprehensively considers cost items and revenue items; wherein, the cost items include at least ore cost, pulverized coal cost, coke cost and oxygen production cost; and the revenue items include at least blast furnace gas revenue and blast furnace slag revenue.

[0022] Furthermore, the blast furnace gas revenue is calculated based on the blast furnace gas production and its calorific value.

[0023] The beneficial effects of this invention are: The method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters provided by this invention can proactively adapt to price fluctuations in the raw material and fuel market. Through systematic calculation and optimization, it can solve for the economic oxygen enrichment rate that maximizes economic benefits under different market conditions (i.e., different coal price differences), while ensuring the stability of the blast furnace thermal regime. This provides a scientific and quantifiable decision-making basis for achieving low-cost operation of the blast furnace and improving overall economic efficiency. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, as described in this invention.

[0025] Figure 2 This is a three-dimensional schematic diagram illustrating the relationship between the cost of fuel per ton of iron and the ratio and price difference of bituminous coal in an embodiment of the present invention.

[0026] Figure 3 This is a three-dimensional schematic diagram illustrating the relationship between the cost of smelting one ton of iron and the ratio and price difference of bituminous coal in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0029] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] This invention provides a method for calculating the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, comprising the following steps: S1, determine the baseline working conditions and target constraints; Select a baseline operating condition, such as the full anthracite injection condition, obtain its production data, and determine a baseline theoretical combustion temperature through calculation using a blast furnace heat balance model. A benchmark blast furnace heat loss value .Should and These will be set as target constraints that must be satisfied in subsequent calculations.

[0031] The benchmark theoretical combustion temperature and benchmark blast furnace heat loss value It is obtained by performing material balance and heat balance calculations on the baseline operating conditions.

[0032] S2, set the gradients for economic and process variables; Set the price difference between bituminous coal and anthracite ( ΔP ) as an economic variable, and take values ​​according to a certain gradient (e.g., ΔP =0.2, 0.175, 0.15… yuan / kg); at the same time, the mixing ratio of bituminous coal in the total pulverized coal injection is set ( x %) is used as a process variable and takes values ​​according to a certain gradient (e.g., x = 10%, 20%, 30%...).

[0033] S3 performs optimization calculations under constraints; For each price difference set in step S2 ( ΔP ) and the blending ratio of each bituminous coal ( x %), as determined in step S1 and To constrain the process, iterative calculations are performed by coordinating the oxygen enrichment rate (ER) and the coal ratio (PCI) until a specific set of solutions (ER, PCI) that can simultaneously satisfy the constraints is found.

[0034] The iterative calculation is based on the blast furnace heat balance model to ensure that the calculation results meet the target constraints.

[0035] This process aims to solve the following system of equations: In the formula, The theoretical combustion temperature is a function that can be determined using the following heat balance formula for the air vent swirl zone: In the formula: —Heat release from coke combustion at the tuyere, kJ / tHM; —Heat release from fuel combustion (kJ / tHM); —The sensible heat brought in by the coke, kJ / tHM; —Heat carried in by circulating gas, kJ / tHM; —The reaction of moisture in fuel and blower air consumes heat, kJ / tHM; —Desorption heat of pulverized coal volatilization and decomposition, kJ / tHM; —Heat consumption for methane decomposition in circulating gas, kJ / tHM; —Slag formation heat, kJ / tHM, —Average heat capacity of gas in the tuyeres' vortex zone, kJ / (℃·m³) 3 ); —Gas volume in the vent swirl zone, m 3 / tHM; —Average heat capacity of fuel ash, kJ / (℃·kg); —Fuel ash content, kg / tHM; —Average heat capacity of unburned pulverized coal, kJ / (℃·kg); —Quantity of unburned pulverized coal, kJ / tHM; This is the blast furnace heat loss function, and its value is determined through full blast furnace heat balance calculation.

[0036] Specifically, the calculation includes: c) Calculate the total heat revenue of the blast furnace ( This mainly includes the physical heat of the blower and the heat of fuel combustion; d) Calculate the main heat expenditure items other than heat dissipation from the furnace body, mainly including the physical heat carried away by molten iron and slag. ), physical and chemical heat carried away by the gas at the top of the furnace ( ), and the net endothermic reaction of each chemical reaction ( )wait; Blast furnace heat loss ( That is, the total heat revenue minus the above-mentioned major heat expenditure items is obtained: In iterative calculations, changes in oxygen enrichment rate (ER) and coal ratio (PCI) will affect total heat revenue and various heat expenditures, thus jointly determining... The final calculation result.

[0037] S4, calculate the cost of smelting one ton of iron under various working conditions; The calculation of the cost per ton of iron smelting comprehensively considers both cost and revenue items. The cost items include at least the cost of ore, pulverized coal, coke, and oxygen production; the revenue items include at least the revenue from blast furnace gas and blast furnace slag. The revenue from blast furnace gas is calculated based on the output and calorific value of the blast furnace gas.

[0038] For each specific solution that satisfies the conditions obtained in step S3, combined with the corresponding price difference in step S2, and other preset raw material and fuel costs and by-product revenues, calculate the cost per ton of iron fuel under this operating condition. ), cost of smelting one ton of iron ( ).

[0039] Among them, by-product revenue refers to the revenue from coal gas and blast furnace slag caused by changes in coal ratio and oxygen enrichment rate.

[0040] The fuel and smelting cost per ton of iron can be calculated using the following formula: In the formula, The cost of smelting iron is expressed in yuan / ton. The cost of fuel per ton of iron is yuan / ton; Cost per ton of iron ore, in yuan / ton; The cost of coke is per ton of iron, expressed in yuan / ton. The cost per ton of iron ore pulverized coal related to the price difference, in yuan / ton; The cost of oxygen production per ton of iron is yuan / ton; The profit per ton of iron slag is RMB / ton; The revenue from the gas is calculated as the profit per ton of iron ore gas and the revenue from the calorific value of the gas, in yuan / ton.

[0041] S5, determine the economic oxygen enrichment rate and establish a decision-making model; For each price difference ( ΔP The cost per ton of iron is compared across all bituminous coal blending ratios to determine the lowest cost point. If a lowest point exists, the oxygen enrichment rate (ER) corresponding to that point is the economic oxygen enrichment rate for that price difference. This process is repeated to obtain the economic oxygen enrichment rate for all price differences, and the results can be generated as a data lookup table or a 3D decision model diagram to visually represent the relationship between price differences, bituminous coal ratios, and cost per ton of iron.

[0042] The following description uses specific examples to illustrate the point.

[0043] Please see Figure 1As shown in the figure, this embodiment provides a calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, including the following steps: S1, determine the baseline working conditions and target constraints; In this embodiment, a stable production condition of a blast furnace under full anthracite injection is selected as the baseline condition. The theoretical combustion temperature under this baseline condition is determined through calculations using a blast furnace heat balance model. and blast furnace heat loss value .in, =2270.04℃, =3.96%, these two parameters will be used as target constraints that must be met for all subsequent calculation conditions.

[0044] S2, set the gradients for economic and process variables; In this embodiment, the base prices of the main raw materials and fuels used for calculation are shown in Tables 1 and 2.

[0045] Table 1 Raw material price parameters Table 2 Fuel and Energy Price Parameters In this embodiment, using the bituminous coal price of 1.285 yuan / kg in Table 2 as a benchmark, the price of anthracite is set to vary from 1.510 yuan / kg to 1.385 yuan / kg, forming a series of different price differences ( ΔP The proportion of bituminous coal in the total pulverized coal injection is set as an economic variable. At the same time, the proportion of bituminous coal in the total pulverized coal injection is set to vary in a gradient from 10% to 90%, which is used as a process variable.

[0046] S3-S5, perform optimization calculations and determine the economic oxygen enrichment rate; The core of this step lies in performing techno-economic calculations for each set bituminous coal blending ratio, under the premise of satisfying the constraints described in step S1. Taking the case of a "bituminous coal blending ratio of 10%" as an example, the calculation process is explained below: First, the ratio of bituminous coal to pulverized coal was set to 10%. In the calculation model, the goal was to maintain a constant theoretical combustion temperature and blast furnace heat loss. This was achieved by synergistically adjusting the oxygen enrichment rate and the total pulverized coal injection ratio, and by iteratively optimizing the model.

[0047] Iterative optimization calculations showed that when the oxygen enrichment rate was adjusted to 3.73% and the total pulverized coal injection ratio was adjusted to 153.40 kg / t, the aforementioned constraints could be met. At this point, the calculated theoretical combustion temperature was 2270.27 K, which was basically consistent with the baseline value of 2270.05 K; the blast furnace heat loss was 3.96%, which remained constant with the baseline value. This indicates that the thermal regime of the blast furnace could be maintained under these parameters.

[0048] Then, based on the material and heat balance results under this operating condition (such as a coke ratio of 361.9 kg / t and ore consumption of 1640.39 kg / t), and combined with the preset prices, the cost per ton of iron at this point is calculated. Specifically, the fuel cost per ton of iron at this point is 1143.1 yuan / ton of iron, and the smelting cost per ton of iron is 2145.25 yuan / ton of iron.

[0049] Using the same method, calculations were performed for working conditions with bituminous coal blending ratios of 20%, 30%, ... up to 90%, resulting in a series of discrete data points (bituminous coal blending ratio, cost).

[0050] Finally, a quadratic polynomial regression analysis was performed on a series of cost data points obtained under a certain price difference to establish a continuous functional relationship C(C) between cost and the proportion of bituminous coal. x ) = a x ² + b x + c, and solve analytically. x = -b / (2a) is used to determine the minimum cost point and its corresponding economic oxygenation rate.

[0051] Figure 2 and Figure 3 These are three-dimensional diagrams obtained by summarizing all calculation results, using fuel cost per ton of iron and smelting cost per ton of iron as indicators.

[0052] Tables 3 and 4 show the calculated fuel costs and economic oxygen enrichment rates under different price differences, and the smelting costs and economic oxygen enrichment rates under different price differences.

[0053] Table 3. Fuel Costs and Economic Oxygen Enrichment Rates under Different Price Differences As shown in Table 3, when the price difference is 0.125 yuan / kg, the cost curve has a trough. Calculated using the method of this invention, the economic oxygen enrichment rate is determined to be 3.73%, corresponding to an economic bituminous coal blending ratio of 10%. When the price difference decreases to 0.1 yuan / kg, the cost curve increases monotonically with the increase of the bituminous coal blending ratio, and no minimum cost value is found.

[0054] Table 4. Smelting costs and economic oxygen enrichment rates under different price differences As shown in Table 4, when the price difference is 0.29 yuan / kg, calculations show that the lowest iron smelting cost per ton is 2155.86 yuan when the bituminous coal ratio is 90%, corresponding to an economic oxygen enrichment rate of 5.76%. When the price difference is 0.28 yuan / kg, the lowest iron smelting cost per ton occurs when the bituminous coal ratio is 50%. When the price difference widens to 0.295 yuan / kg, no economic oxygen enrichment rate is achieved.

[0055] As can be seen from the above embodiments, the method provided by the present invention can proactively adapt to price fluctuations in the raw material and fuel market. Through systematic calculation and optimization, it can solve for the economic oxygen enrichment rate that maximizes economic benefits under different market conditions (i.e., different coal price differences), while ensuring the stability of the blast furnace thermal system. This provides a scientific and quantifiable decision-making basis for achieving low-cost operation of the blast furnace and improving overall economic efficiency.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters, characterized in that, Includes the following steps: S1, for a baseline operating condition, calculates and determines the corresponding baseline theoretical combustion temperature using a blast furnace heat balance model. and benchmark blast furnace heat loss value ; S2, set a series of different mixing ratios of bituminous coal in the total pulverized coal injection, and use the mixing ratio as a process variable; S3, for each mixing ratio in step S2, using the aforementioned reference theoretical combustion temperature and benchmark blast furnace heat loss value As the target constraint, iterative calculations are performed by coordinating the oxygen enrichment rate and coal ratio to find a set of conditions that can simultaneously satisfy the aforementioned benchmark theoretical combustion temperature. and benchmark blast furnace heat loss value A specific oxygen enrichment rate and a specific total pulverized coal injection ratio; S4. Based on the specific oxygen enrichment rate and specific total pulverized coal injection ratio obtained in step S3, as well as the preset raw material and fuel prices and by-product revenue, calculate the smelting cost per ton of iron corresponding to each of the mixing ratios. S5. By comparing the smelting costs of all tons of iron calculated in step S4, the lowest cost value is determined, and the oxygen enrichment rate corresponding to the lowest cost value is determined as the economic oxygen enrichment rate.

2. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, In step S3, for each mixing ratio, a specific oxygen enrichment rate and a specific total pulverized coal injection ratio are obtained.

3. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, The calculation method further includes: when the price of raw materials or the revenue from by-products changes, updating the corresponding preset value and repeating steps S4-S5 to obtain a new economic oxygen enrichment rate.

4. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, The by-product revenue refers to the revenue from coal gas and blast furnace slag resulting from changes in the coal ratio and oxygen enrichment rate.

5. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, The benchmark operating condition is the condition of full anthracite injection.

6. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, In step S1, the reference theoretical combustion temperature and benchmark blast furnace heat loss value It is obtained by performing material balance and heat balance calculations on the aforementioned benchmark operating conditions.

7. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, In step S3, the iterative calculation is performed based on the blast furnace heat balance model to ensure that the calculation results meet the target constraints.

8. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 1, characterized in that, In step S4, the calculation of the cost per ton of iron smelting comprehensively considers cost items and revenue items; wherein, the cost items include at least ore cost, pulverized coal cost, coke cost and oxygen production cost; and the revenue items include at least blast furnace gas revenue and blast furnace slag revenue.

9. The calculation method for determining the economic oxygen enrichment rate of a blast furnace based on constant thermal parameters according to claim 8, characterized in that, The blast furnace gas revenue is calculated based on the blast furnace gas production and its calorific value.

Images