Unfired coal powder generation quantity calculation method based on blast furnace operation parameters

Abstract

The invention relates to the technical field of blast furnace ironmaking, in particular to an unfired pulverized coal generation quantity calculation method based on blast furnace operation parameters. The method specifically comprises the following steps: S1, acquiring a plurality of key operation parameters of the blast furnace; s2, inputting the plurality of key operation parameters into a pre-constructed unfired pulverized coal amount prediction model; the prediction model is a mathematical model reflecting a nonlinear relation between the key operation parameters and the unburned pulverized coal amount; s3, outputting a predicted value of the unburned pulverized coal amount of the blast furnace by the prediction model; wherein the plurality of key operation parameters at least comprise the temperature of blown hot air, the oxygen enrichment rate of the blown hot air, the strength after the thermal reaction of the charged coke, the grade of charged raw material iron, the fixed carbon content of the mixed pulverized coal, the volatile component content of the mixed pulverized coal, the fineness of the mixed pulverized coal and the coal injection quantity per ton of iron. Existing operation data can be fully utilized, and the quantity of unburned pulverized coal can be rapidly and accurately analyzed.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, specifically to a method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters. Background Technology

[0002] Blast furnace ironmaking is the primary source of steel products in modern society, and its production cost largely depends on fuel consumption. Pulverized coal injection, as a core technology for replacing coke and reducing costs, is economically viable directly determined by the efficiency of coal utilization within the blast furnace. However, due to the limited reaction space and time within the blast furnace, some of the injected coal fails to burn completely, forming "unburned coal powder" which is discharged with furnace dust. The amount of unburned coal powder is a key indicator for evaluating the effectiveness of pulverized coal injection and the economic operation of the blast furnace.

[0003] Currently, the main analytical methods for unburned pulverized coal fall into the following categories: One method is component analysis, such as the "Detection Method for Rapidly Determining the Coal-Coke Ratio in Blast Furnace Dust" disclosed in Chinese Patent No. CN109187260B. This method distinguishes and counts unburned coal powder and coke powder particles in the dust using petrographic or microscopic techniques. While this method yields accurate results, it relies on professional personnel and complex experiments, making the process cumbersome, time-consuming, and labor-intensive, and difficult to meet the needs of enterprises for rapid production guidance.

[0004] The second method is computational analysis, such as the "Method for Calculating the Combustion Rate of Pulverized Coal Injected into a Blast Furnace Tub" disclosed in Chinese Patent Publication No. CN114724640B, which uses big data technology to establish a correlation model between operating parameters and combustion rate. While this method is relatively convenient, its accuracy is highly dependent on the representativeness of the selected factors and the precision of the mathematical relationships between them. Improper model construction can easily lead to significant deviations in the calculation results, affecting the reliability of production guidance.

[0005] In addition, there are related technologies such as the "Evaluation Method for the Quality of Coal and Coke Replacement in Blast Furnaces" disclosed in Chinese Patent No. CN117194913B, which mainly focuses on process evaluation and optimization and does not conduct quantitative analysis of unburned coal powder, so its reference value is limited.

[0006] In summary, existing technologies are either difficult to implement quickly or lack sufficient accuracy in their analysis results, and a simple, universal, and accurate quantitative analysis method has not yet been established to bridge the gap between the complex operating conditions of blast furnaces and the amount of unburned pulverized coal generated. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters, which can make full use of existing operating data and quickly and accurately analyze the amount of unburned pulverized coal.

[0008] To achieve the above objectives, the present invention employs the following technical solution: A method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters, specifically including the following steps: S1. Obtain multiple key operating parameters of the blast furnace; S2. Input the multiple key operating parameters into the pre-constructed unburned coal powder quantity prediction model; The prediction model is a mathematical model that reflects the nonlinear relationship between the key operating parameters and the amount of unburned coal powder. S3. The prediction model outputs the predicted value of the amount of unburned pulverized coal in the blast furnace; Among them, the key operating parameters include at least: hot air temperature, hot air oxygen enrichment rate, coke strength after hot reaction, iron grade of raw materials, fixed carbon content of mixed pulverized coal, volatile matter content of mixed pulverized coal, fineness of mixed pulverized coal, and pulverized coal injection rate per ton of iron.

[0009] Furthermore, the prediction model calculates the unburned pulverized coal generation quantity (UCP) using the following formula: In the formula: UCP represents the amount of unburned pulverized coal generated, in kg / t; HAT is the temperature of the hot air blown in, in °C; OER is the oxygen enrichment rate of the blown hot air, %; CSR is the strength of coke after hot reaction in the furnace, %; TFe represents the iron grade of the raw material fed into the furnace, %; FCad is the fixed carbon content of the mixed pulverized coal, in percentages (%). V represents the volatile matter content of the mixed pulverized coal, %; PSPC represents the fineness of the mixed pulverized coal, %. PCI stands for Coal Injection Rate per Ton of Iron, in kg / t; m1 and m2 are constants, and k1 to k6 are coefficients.

[0010] Further, the fineness of the mixed coal powder is the percentage of particles smaller than 0.074 mm in the mixed coal powder injected into the furnace, where m1 is a constant with a value of 0.96; m2 is a constant with a value of 1.26; k1 is a dimensionless correction coefficient with a value of 3.20 at ℃; k2 is a coefficient with a value of 12.60; k3 is a coefficient with a value of 22.50; k4 is a coefficient with a value of -78.40; k5 is a coefficient with a value of 16.50; and k6 is a coefficient with a value of 71.43.

[0011] Furthermore, the hot air temperature HAT is 900~1350℃.

[0012] Furthermore, the oxygen enrichment rate (OER) of the blown hot air is 0~12%.

[0013] Furthermore, the strength CSR of the coke after hot reaction in the furnace is 52%~78%.

[0014] Furthermore, the iron grade TFe in the raw materials fed into the furnace is 50%~65%.

[0015] Furthermore, the fixed carbon content (FCad) of the mixed pulverized coal is 55% to 85%.

[0016] Furthermore, the percentage of PSPC (particulate matter per unit volume) smaller than 0.074 mm in the mixed pulverized coal injected into the furnace is 45%~90%.

[0017] Furthermore, the PCI (Pulverized Coal Injection Rate) per ton of iron is 90~240 kg / t.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. High analytical accuracy and reliable results. Based on long-term industrial practice and research, this invention constructs a multi-parameter, nonlinear, specialized mathematical model. This model introduces eight key operating parameters, including blast temperature, oxygen enrichment rate, coke strength, raw material grade, and pulverized coal characteristics, and assigns optimized specific indices and coefficients to each parameter, thereby more realistically simulating the complex combustion and reaction kinetics within the blast furnace. Data from Examples 1 to 6 show that the error between the calculated values ​​and actual sampled measurements using the method of this invention is extremely small, with an average absolute error of only 0.11 kg / t and a relative error generally below 2.5%. This high degree of agreement fully demonstrates the accuracy and reliability of the method of this invention in the quantitative analysis of unburned pulverized coal, far superior to existing calculation models that rely on experience or simple correlations.

[0019] 2. Analytical efficiency is greatly improved, enabling rapid guidance. Traditional component analysis methods, while offering reasonable accuracy, rely on specialized personnel in laboratories using techniques such as petrographic analysis. This process is cumbersome and time-consuming, taking hours or even days, and cannot meet the real-time adjustment needs of blast furnace production. This invention completely eliminates the complex laboratory testing process. It only requires access to existing, real-time monitorable process parameters from daily blast furnace operation, and calculations can be completed within minutes using the stated formula. This "online analysis" capability allows operators to quickly assess pulverized coal injection effectiveness, promptly detect trends of combustion deterioration, and gain valuable time to adjust operating parameters, significantly improving production efficiency and response speed.

[0020] 3. Simple to operate and easy to promote and apply in enterprises. Because the method of this invention does not require expensive specialized testing equipment, nor does it require complex sample pretreatment or professional analysts, any engineer or technician with basic knowledge of blast furnace operation can easily master and implement it. This greatly reduces the application threshold and implementation cost of the technology, and solves the core pain points of traditional testing methods that are "time-consuming, labor-intensive, and difficult to master." This allows a wide range of steel enterprises, regardless of size, to conveniently apply this method, thus possessing extremely high promotional value and application prospects.

[0021] 4. It provides direct and quantitative basis for guiding blast furnace production optimization, cost reduction, and efficiency improvement. This invention overcomes the limitation of human experience-based judgment methods, which can only provide qualitative but not quantitative results, and can accurately provide numerical results for unburned pulverized coal. Based on this quantitative result, production personnel can: First, precisely optimize pulverized coal injection operations. For example, when the calculated UCP value is too high, measures such as increasing the blast temperature, adjusting oxygen enrichment, and optimizing pulverized coal particle size can be taken in a timely manner to improve combustion. Second, scientifically evaluate the combustion performance of different coal types, providing a basis for decision-making in purchasing cost-effective pulverized coal. Third, continuously promote the reduction of blast furnace fuel ratio, and achieve effective savings in fuel cost per ton of iron by minimizing the loss of unburned pulverized coal. Detailed Implementation

[0022] This invention discloses a method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0023] A method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters is proposed. The following calculation formula is used to analyze the amount of unburned pulverized coal generated under different blast furnace operating conditions: In the formula: UCP represents the amount of unburned pulverized coal generated, in kg / t; HAT is the temperature of the hot air blown in, in °C; OER is the oxygen enrichment rate of the blown hot air, %; CSR is the strength of coke after hot reaction in the furnace, %; TFe represents the iron grade of the raw material fed into the furnace, %; FCad is the fixed carbon content of the mixed pulverized coal, in percentages (%). V represents the volatile matter content of the mixed pulverized coal injected into the furnace, %; PSPC is the percentage of particles smaller than 0.074 mm in the mixed pulverized coal injected into the furnace (fineness of mixed pulverized coal), % PCI stands for pulverized coal injection rate per ton of iron produced (pulverized coal injection rate per ton of iron), in kg / t.

[0024] m1 is a constant with a value of 0.96; m2 is a constant with a value of 1.26; k1 is a dimensionless correction factor with a value of 3.20 in °C; k2 is a coefficient with a value of 12.60; k3 is a coefficient with a value of 22.50; k4 is a coefficient with a value of -78.40; k5 is a coefficient with a value of 16.50; k6 is a coefficient with a value of 71.43.

[0025] Example 1 A steel plant has an effective furnace volume of 300m³. 3 The specific operating parameters of the blast furnace are shown in Table 1.

[0026] Table 1 Blast Furnace Operating Parameters Substituting the parameters in Table 1 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 2.

[0027] Table 2 Comparison of Calculation Results for Unburned Pulverized Coal Quantity As shown in Table 2, the calculated value of the method of the present invention is 6.08 kg / t, which is in high agreement with the measured value of 6.21 kg / t, with an absolute error of only 0.13 kg / t. This fully verifies the accuracy and reliability of the method of the present invention in practical applications. Meanwhile, this result indicates that the amount of unburned coal powder is relatively high under the current operating conditions, suggesting that operators should take timely optimization measures, such as increasing the air temperature or optimizing the coal powder particle size, to improve combustion efficiency.

[0028] Example 2 A steel plant has an effective furnace volume of 1800m³. 3 The specific operating parameters of the blast furnace are shown in Table 3.

[0029] Table 3 Blast Furnace Operating Parameters Substituting the parameters in Table 3 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 4.

[0030] Table 4. Quantity of unburned pulverized coal generated during the production of tonnes of iron. As shown in Table 4, the calculated value of the method of the present invention is 4.79 kg / t, which is in high agreement with the measured value of 4.70 kg / t, with an absolute error of only 0.09 kg / t. This fully verifies the accuracy and reliability of the method of the present invention in practical applications. Under this operating condition, the amount of unburned pulverized coal is at a low level, indicating that the pulverized coal is fully burned. Maintaining the current operating conditions is conducive to the stability of the blast furnace and energy conservation and consumption reduction.

[0031] Example 3 A steel plant has an effective furnace volume of 2580m³. 3 The specific operating parameters of the blast furnace are shown in Table 5.

[0032] Table 5 Blast Furnace Operating Parameters Substituting the parameters in Table 5 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 6.

[0033] Table 6 Comparison of Calculation Results for Unburned Pulverized Coal Quantity As shown in Table 6, the calculated value of the method of this invention is 4.85 kg / t, while the measured value from the sampling is 4.97 kg / t. The difference between the two is only 0.12 kg / t, which is a very small error and can be almost ignored. This also verifies the accuracy and feasibility of this method. The results confirm that under the current optimized conditions, the amount of unburned pulverized coal generated is small, and the pulverized coal injection process is highly economical, which can be maintained as an ideal production state.

[0034] Example 4 A steel plant has an effective furnace volume of 3200 m³. 3 The specific operating parameters of the blast furnace are shown in Table 7.

[0035] Table 7 Blast Furnace Operating Parameters Substituting the parameters in Table 7 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 8.

[0036] Table 8 Comparison of Calculation Results for Unburned Pulverized Coal Quantity As shown in Table 8, the calculated value of the method of the present invention is 6.44 kg / t, while the actual measured value of the sample is 6.54 kg / t. The difference between the two is only 0.10 kg / t, which is very small and can be ignored. This also verifies the accuracy and feasibility of the method.

[0037] The analysis results clearly indicate that the amount of unburned pulverized coal is too high under this operating condition, which provides a clear early warning for the site and suggests that combustion should be enhanced and fuel loss reduced by means of increasing the oxygen enrichment rate or adjusting the pulverized coal ratio.

[0038] Example 5 A steel plant has an effective furnace volume of 4038 m³. 3 The specific operating parameters of the blast furnace are shown in Table 9.

[0039] Table 9 Blast Furnace Operating Parameters Substituting the parameters in Table 9 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 10.

[0040] Table 10 Comparison of Calculation Results for Unburned Pulverized Coal Quantity As shown in Table 10, the calculated value of the method of this invention is 4.69 kg / t, while the measured value from the sampling is 4.84 kg / t. The difference between the two is only 0.15 kg / t, which is a very small error and can be almost ignored. This also verifies the accuracy and feasibility of this method. The calculation results indicate that the large blast furnace is operating well, and the unburned pulverized coal is effectively controlled, confirming the applicability of this invention in large-capacity furnace applications.

[0041] Example 6 A steel plant has an effective furnace volume of 5500 m³. 3 The specific operating parameters of the blast furnace are shown in Table 11.

[0042] Table 11 Blast Furnace Operation Status Substituting the parameters in Table 11 into the calculation formula of this invention, the calculated amount of unburned coal powder is compared with the measured results in Table 12.

[0043] Table 12 shows the amount of unburned pulverized coal generated during the production of 12 tons of iron. As shown in Table 10, the calculated value of the method of this invention is 3.94 kg / t, while the measured value from the sampling is 4.02 kg / t. The difference between the two is only 0.08 kg / t, which is a very small error and can be almost ignored. This also verifies the accuracy and feasibility of this method. This proves that the method of this invention also has excellent predictive ability for ultra-large blast furnaces. The low amount of unburned pulverized coal under this operating condition indicates excellent pulverized coal utilization efficiency and is a model for achieving low-cost smelting.

[0044] Based on six coverage areas of 300m 3 up to 5500m 3Industrial implementations with different furnace capacities have verified that the method of this invention exhibits extremely high accuracy, wide applicability, and clear practical value. The average absolute error between the calculated and measured values ​​is only 0.11 kg / t, proving the accuracy and reliability of its core mathematical model. The method maintains stable accuracy under different furnace capacities and varying operating conditions, highlighting its excellent universality. More importantly, this method can directly provide quantitative guidance for blast furnace operation: when the calculation results indicate a high amount of unburned pulverized coal, it can provide timely warnings and guide optimization; when the results show a low value, it confirms the superiority of the current process conditions, thus effectively serving rapid decision-making on the production site and continuous reduction of fuel costs.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters, characterized in that, Specifically, the steps include the following: S1. Obtain multiple key operating parameters of the blast furnace; S2. Input the multiple key operating parameters into the pre-constructed unburned coal powder quantity prediction model; The prediction model is a mathematical model that reflects the nonlinear relationship between the key operating parameters and the amount of unburned coal powder. S3. The prediction model outputs the predicted value of the amount of unburned pulverized coal in the blast furnace; Among them, the key operating parameters include at least: hot air temperature, hot air oxygen enrichment rate, coke strength after hot reaction, iron grade of raw materials, fixed carbon content of mixed pulverized coal, volatile matter content of mixed pulverized coal, fineness of mixed pulverized coal, and pulverized coal injection rate per ton of iron.

2. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 1, characterized in that, The prediction model calculates the unburned pulverized coal production (UCP) using the following formula: In the formula: UCP represents the amount of unburned pulverized coal generated, in kg / t; HAT is the temperature of the hot air blown in, in °C; OER is the oxygen enrichment rate of the blown hot air, %; CSR is the strength of coke after hot reaction in the furnace, %; TFe represents the iron grade of the raw material fed into the furnace, %; FCad is the fixed carbon content of the mixed pulverized coal, in percentages (%). V represents the volatile matter content of the mixed pulverized coal, %; PSPC refers to the fineness of mixed pulverized coal, %; PCI stands for Coal Injection Rate per Ton of Iron, in kg / t; m1 and m2 are constants, and k1 to k6 are coefficients.

3. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The fineness of the mixed coal powder refers to the percentage of particles smaller than 0.074 mm in the mixed coal powder injected into the furnace.

4. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The temperature of the hot air blown in is 900~1350℃.

5. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The oxygen enrichment rate (OER) of the blown hot air is 0~12%.

6. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The strength CSR of coke after hot reaction in the furnace is 52%~78%.

7. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The iron content (TFe) of the raw materials fed into the furnace is 50%~65%.

8. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The fixed carbon content (FCad) of the mixed pulverized coal is 55%~85%.

9. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 3, characterized in that, The percentage of PSPC (particulate power consumption) smaller than 0.074 mm in the mixed pulverized coal injected into the furnace is 45%~90%.

10. The method for calculating the amount of unburned pulverized coal generated based on blast furnace operating parameters according to claim 2, characterized in that, The PCI (Pulverized Coal Injection Rate) per ton of iron is 90~240 kg / t.

Images