Method for measuring and calculating combustion rate of mixed pulverized coal for injection at different blast temperatures

Abstract

The invention relates to a method for measuring and calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures. The method comprises the following steps: 1) determining evaluation parameters of the mixed pulverized coal related to the combustion rate; 2) setting a contribution value of each evaluation parameter to combustion rate measurement and calculation; 3) setting the contribution value of the blast temperature to the combustion rate of the mixed pulverized coal; 4) setting correlation coefficients of the blast temperature and the evaluation parameters for the measurement and calculation of the combustion rate of the mixed pulverized coal; and 5) establishing a mixed pulverized coal combustion rate calculation formula, and setting an error compensation coefficient. On the basis of fully considering the mathematical correlation between the component composition of the mixed pulverized coal and the combustion rate, the method for predicting the combustion rate of the mixed pulverized coal for injection at different blast temperatures is accurately obtained, and the method is simple and high in feasibility, so that the method is suitable for coal type selection and matched use of a blast furnace coal injection process. Important technical references are provided for predicting the combustion effect and the utilization efficiency of pulverized coal in the blast furnace, and a reliable basis can be provided for overall improvement of a blast furnace coal injection process system.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, and in particular to a method for calculating the combustion rate of mixed coal powder for injection at different blast temperatures. Background Art

[0002] Under the modern smelting process system, most of the steel materials needed by various industries in society are derived from the molten iron produced by the blast furnace smelting process. Therefore, the blast furnace as the main pig iron processing equipment is still irreplaceable or indispensable at this stage. With the rapid development of science and technology and economy, blast furnaces are showing a trend towards large-scale, automatic, long-life and high-efficiency development, and the ironmaking production process technology with blast furnaces as the core has also been enhanced. The most significant advantage of blast furnace ironmaking compared to other smelting processes is the high efficiency of its process operation. This is because the blast furnace has a high thermal utilization efficiency, that is, the blast furnace can achieve the same amount of molten iron with the least fuel consumption during the pig iron smelting process.

[0003] The fuel used in blast furnaces is mainly composed of the following two types of fuels. The main fuel is metallurgical coke, which is the product of high-temperature dry distillation of coking coal and other products. It plays the role of heating agent, carburizing agent, reducing agent and the most important material column skeleton in the blast furnace smelting process; the other is mixed coal powder for injection, which is mainly composed of different types of bituminous coal, anthracite, lean coal, lean coal, lignite and a small amount of "carbon-containing resources" (such as blue coke, upgraded coal, dust removal ash, biomass fuel, etc.), and plays the role of heating agent, reducing agent and carburizing agent in the blast furnace charge process. It should be noted that due to the physical properties of the mixed coal powder for injection, it does not have the function of material column skeleton in the charge smelting process. In addition, due to the constraints of factors such as the shortage of coking coal resources, there is a large gap in the supply of metallurgical coke, which directly leads to the high price of coke, thereby pushing up the operating costs of enterprises. In this context, the coal powder injection process that can partially replace the function of coke has been widely promoted and applied.

[0004] As an important source of heat in the furnace, the composition and physical state of the mixed coal powder for injection are of decisive significance to its application effect in the blast furnace. Among the many analysis and evaluation indicators (such as component content, particle size distribution, element composition, ash composition, grindability, calorific value, ignition point, explosiveness, reaction state, coking, combustion rate, etc.), the most core indicator is the utilization effect of the mixed coal powder in the furnace, or the combustion effect (characterized by the combustion rate). Years of research and production practice have shown that the combustion effect of mixed coal powder is related to many factors, such as the composition of the mixed coal powder, particle size composition, external atmosphere, ambient temperature, etc., and under the same external environment, the combustion effect of the mixed coal powder is closely related to the composition.

[0005] At present, the following two methods are mainly used to judge the combustion effect of mixed pulverized coal for injection:

[0006] The first type is the empirical judgment method, which is based on industry experience, through the basic data such as the basic composition of mixed coal powder, coal type, and coal ratio, to make artificial empirical judgments, and give corresponding combustion effect descriptions for mixed coal powder with different components under different external combustion conditions, so as to guide the blast furnace coal powder injection operation and blast furnace production. However, due to the use of artificial empirical analysis methods, only qualitative judgments can be given, and quantitative analysis results cannot be given, nor can the true value of mixed coal powder combustion be accurately analyzed, so that the combustion trend cannot be accurately predicted. In addition, the sources of coal used by enterprises are relatively complex, and mixed coal powder is affected by multiple superpositions of multiple factors. At the same time, there are large errors in human judgment, which will affect the specific application of mixed coal powder and the actual production and operation effect of blast furnaces.

[0007] The second type is the instrumental detection method, which uses a special combustion rate measuring device and a differential thermal analyzer to measure the combustion rate of the mixed coal powder. By simulating different combustion environments, the coal powder samples are measured and the combustion rate of the mixed coal powder is analyzed. For example, the Chinese patent application with publication number CN111241715A discloses a “method for determining test parameters of pulverized coal combustion rate of blast furnace injection under different coal ratios”, the Chinese patent application with publication number CN106546695A discloses a “device and method for testing pulverized coal combustion rate by dry dust collection method”, the Chinese utility model patent with authorization announcement number CN210894182U discloses a “detection device for pulverized coal combustion rate of blast furnace injection”; the Chinese utility model patent with authorization announcement number CN204039427U discloses a “device for determining the combustion rate of pulverized coal injection in blast furnace”, the Chinese invention patent with authorization announcement number CN 103571989B discloses a “super-high temperature pulverized coal combustion experimental device”, the Chinese patent application with publication number CN 104764852A discloses a “visual detection method for pulverized coal combustion rate”, and so on.

[0008] Objectively speaking, using special instruments to analyze the combustion rate of mixed coal powder is relatively accurate and is one of the most reliable methods to accurately grasp the combustion effect of coal powder. However, it also has obvious shortcomings in practical applications, that is, the equipment is expensive and the cost of use is high; and the detection process requires professional personnel to operate, and the operation process is complicated and cumbersome, resulting in many enterprises, especially small and medium-sized metallurgical enterprises, not being able to use it.

[0009] Understanding the combustion of different mixed coal powders under different wind temperatures is the most important way to achieve low-consumption and high-efficiency coal powder injection in blast furnaces, because only by achieving efficient use of mixed coal powder in the furnace can the most economical fuel consumption be achieved, thereby achieving the low-cost goal of blast furnace smelting. In view of this, if a simple and relatively accurate analysis method is developed to predict the combustion efficiency of mixed coal powder under different proportions and different wind temperatures, it will undoubtedly have great practical application value, and this is also the significance of the present invention.

[0010] At present, some patent documents that predict the combustion rate of coal powder by calculation can be retrieved, such as "A method for calculating the combustion rate of coal powder injected at the tuyere of a blast furnace" disclosed in the Chinese invention patent with the authorization announcement number CN114724640B, "A method for detecting the combustion rate of coal powder in the cyclotron zone of the tuyere of an ironmaking blast furnace" disclosed in the Chinese patent application with the publication number CN112921137A, "A method for evaluating the cost performance of coal powder injection" disclosed in the Chinese patent application with the publication number CN113077132A, etc. The above methods mainly use mathematical calculations to analyze the combustion effect of coal powder, explain the differences in the combustion effect of coal powder and quantitatively describe them numerically, which has certain guiding significance in practical applications. However, the problem with the above calculation methods is that the calculation process is complicated and cumbersome, and it is difficult for even professionals to apply it. In addition, there are many data that need to be referenced, which often leads to large deviations in the calculation process and analysis results. Therefore, it has great limitations in practical applications and is not conducive to real implementation and application.

[0011] There are also some relevant documents on the combustion efficiency of mixed pulverized coal in domestic and foreign public documents, such as "Research on the Combustion Process of Mixed Coal Injection in Panzhihua Iron and Steel Blast Furnace" (Ironmaking, Vol. 23, No. 2, 2004, pp. 45-47); "The Effect of Adding MgO on the Combustion Rate of Pulverized Coal Injected in Blast Furnace" (Iron and Steel, Vol. 46, No. 7, 2011, pp. 7-9); "The Effect of Coal Rock Composition on the Combustion Rate of Pulverized Coal Injected in Blast Furnace" (Journal of Iron and Steel Research, Vol. 22, No. 5, 2010, pp. 23-25); "Study on the Combustion Rate of Mixed Coal by Thermogravimetry" (Metallurgical Energy, Vol. 27, No. 3, 2008, pp. 33-35); "Study on the Combustion Rate of Mixed Coal by Thermogravimetry", (Iron and Steel Vanadium Titanium, Vol. 35, No. 1, 2014, pp. 82-86); "The Effect of Pulverized Coal Particle Size on the Combustion Performance before the Blast Furnace Tuyere" (Iron and Steel, Vol. 38, No. 7, 2003, pp. 35-38). The above-mentioned public documents improve the combustion efficiency of the mixed coal powder injected into the furnace by improving the coal blending structure, adding coal powder combustion aids, optimizing the coal powder particle size, etc., and also give a detailed introduction to the actual application process, but rarely mention the specific analysis methods of the coal powder combustion rate. Even if mentioned, most of them use conventional instruments and laboratory analysis methods. Summary of the invention

[0012] The present invention provides a method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures. On the basis of fully considering the mathematical correlation between the composition of the mixed pulverized coal and the combustion rate, a method for accurately obtaining the prediction method of the combustion rate of mixed pulverized coal for injection at different blast temperatures is provided. The method is simple and has strong feasibility, thereby providing an important technical reference for the selection and matching of coal types in the blast furnace coal injection process, as well as the prediction of the combustion effect and utilization efficiency of coal powder in the blast furnace, and can also provide a reliable basis for the overall improvement of the blast furnace coal injection process system.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions:

[0014] A method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures comprises the following steps:

[0015] 1) Determine the evaluation parameters related to the combustion rate of the mixed coal powder, including fixed carbon content, volatile matter content, ash content and sulfur content;

[0016] 2) According to the historical data recorded in the blast furnace production and operation database, the contribution value of each evaluation parameter to the combustion rate calculation is set;

[0017] 3) According to the historical data recorded in the blast furnace production operation database, the contribution value of the blast temperature to the mixed coal powder combustion rate is set;

[0018] 4) According to the historical data recorded in the blast furnace production operation database, the correlation coefficients of the blast temperature and the evaluation parameters for the mixed coal powder combustion rate are set respectively;

[0019] 5) Establish a formula for calculating the combustion rate of mixed pulverized coal composed of blast temperature and evaluation parameters, and set the error compensation coefficient based on the historical data recorded in the blast furnace production and operation database;

[0020] The calculation formula for the combustion rate of mixed pulverized coal at different blast temperatures is:

[0021]

[0022] Where, BR is the combustion rate of mixed pulverized coal at different blast temperatures, %;

[0023] F C --Fixed carbon content in mixed coal powder, %;

[0024] V--volatile matter content in mixed coal powder, %;

[0025] A--ash content in mixed coal powder, %;

[0026] S--Sulfur content in mixed coal powder, %;

[0027] K--error compensation coefficient, which is a constant and takes a value of 1.02%, %;

[0028] A1--Correlation coefficient of blast temperature, which is a constant and takes the value as 0.23, % / ℃;

[0029] A2--Correlation coefficient of evaluation parameters, which is a constant and takes a value of 0.24%;

[0030] 6) The specific values ​​of each evaluation parameter and the set blast temperature value are respectively determined and substituted into Formula 1 to obtain the predicted value of the combustion rate of the mixed coal powder at the corresponding blast temperature.

[0031] Furthermore, the mixed coal powder is composed of two or more different types of coal powder, and the different types of coal powder include anthracite, lean coal, lean coal, bituminous coal, lignite and alternative coal.

[0032] Furthermore, the alternative coal types include one or more of lignite, CDQ powder, upgraded coal, biomass fuel, and blast furnace dust ash.

[0033] Furthermore, the biomass fuel includes one or more of charcoal, activated carbon, straw, fruit wood shell, and rice husk.

[0034] Furthermore, the blast furnace dust ash includes one or more of the following: coke trough dust ash, furnace top dust ash, and furnace front dust ash.

[0035] Furthermore, the blast temperature ranges from 700°C to 1350°C.

[0036] Furthermore, in terms of weight percentage, the fixed carbon content ranges from 50% to 88%, the volatile matter content ranges from 6% to 40%, the ash content ranges from 5% to 20%, and the sulfur content ranges from 0.2% to 2.5%.

[0037] Furthermore, the control index of the combustion rate of the mixed coal powder is 92.50%. The calculated combustion rate value ≥92.50% is evaluated as meeting the requirements, and the calculated combustion rate value <92.50% is evaluated as not meeting the requirements. For the mixed coal powder that does not meet the requirements, the ingredients are readjusted, bituminous coal is added, or the proportion of bituminous coal in the mixed coal powder is increased.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] On the basis of fully considering the mathematical correlation between the composition of mixed coal powder and the combustion rate, a prediction method for the combustion rate of mixed coal powder for injection at different blast temperatures is accurately obtained. The method is simple and has strong feasibility. It provides an important technical reference for the selection and matching of coal types in the blast furnace coal injection process, as well as the prediction of the combustion effect and utilization efficiency of coal powder in the blast furnace. It can also provide a reliable basis for the overall improvement of the blast furnace coal injection process system. DETAILED DESCRIPTION

[0040] The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures of the present invention comprises the following steps:

[0041] 1) Determine the evaluation parameters related to the combustion rate of the mixed coal powder, including fixed carbon content, volatile matter content, ash content and sulfur content;

[0042] 2) According to the historical data recorded in the blast furnace production and operation database, the contribution value of each evaluation parameter to the combustion rate calculation is set;

[0043] 3) According to the historical data recorded in the blast furnace production operation database, the contribution value of the blast temperature to the mixed coal powder combustion rate is set;

[0044] 4) According to the historical data recorded in the blast furnace production operation database, the correlation coefficients of the blast temperature and the evaluation parameters for the mixed coal powder combustion rate are set respectively;

[0045] 5) Establish a formula for calculating the combustion rate of mixed pulverized coal composed of blast temperature and evaluation parameters, and set the error compensation coefficient based on the historical data recorded in the blast furnace production and operation database;

[0046] The calculation formula for the combustion rate of mixed pulverized coal at different blast temperatures is:

[0047]

[0048] Where, BR is the combustion rate of mixed pulverized coal at different blast temperatures, %;

[0049] F C --Fixed carbon content in mixed coal powder, %;

[0050] V--volatile matter content in mixed coal powder, %;

[0051] A--ash content in mixed coal powder, %;

[0052] S--Sulfur content in mixed coal powder, %;

[0053] K--error compensation coefficient, which is a constant and takes a value of 1.02%, %;

[0054] A1--Correlation coefficient of blast temperature, which is a constant and takes the value as 0.23, % / ℃;

[0055] A2--Correlation coefficient of evaluation parameters, which is a constant and takes a value of 0.24%;

[0056] 6) The specific values ​​of each evaluation parameter and the set blast temperature value are respectively determined and substituted into Formula 1 to obtain the predicted value of the combustion rate of the mixed coal powder at the corresponding blast temperature.

[0057] Furthermore, the mixed coal powder is composed of two or more different types of coal powder, and the different types of coal powder include anthracite, lean coal, lean coal, bituminous coal, lignite and alternative coal.

[0058] Furthermore, the alternative coal types include one or more of lignite, CDQ powder, upgraded coal, biomass fuel, and blast furnace dust ash.

[0059] Furthermore, the biomass fuel includes one or more of charcoal, activated carbon, straw, fruit wood shell, and rice husk.

[0060] Furthermore, the blast furnace dust ash includes one or more of the following: coke trough dust ash, furnace top dust ash, and furnace front dust ash.

[0061] Furthermore, the blast temperature ranges from 700°C to 1350°C.

[0062] Furthermore, in terms of weight percentage, the fixed carbon content ranges from 50% to 88%, the volatile matter content ranges from 6% to 40%, the ash content ranges from 5% to 20%, and the sulfur content ranges from 0.2% to 2.5%.

[0063] Furthermore, the control index of the combustion rate of the mixed coal powder is 92.50%. The calculated combustion rate value ≥92.50% is evaluated as meeting the requirements, and the calculated combustion rate value <92.50% is evaluated as not meeting the requirements. For the mixed coal powder that does not meet the requirements, the ingredients are readjusted, bituminous coal is added, or the proportion of bituminous coal in the mixed coal powder is increased.

[0064] In order to more intuitively embody the present invention, the embodiments of the present invention are further described in conjunction with examples. The following examples are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be obviously obtained by a person skilled in the art within the technical scope disclosed in the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0065] [Example 1]

[0066] This example uses a steel plant with an effective furnace capacity of 300m 3Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 1-1.

[0067] Table 1-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0068]

[0069]

[0070] The composition of the mixed coal powder for blast furnace injection is detailed in Table 1-2.

[0071] Table 1-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0072]

[0073] For details on the set blast temperature of the blast furnace, please see Table 1-3.

[0074] Table 1-3 Blast furnace set blast temperature, ℃

[0075]

[0076] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 1-4.

[0077] Table 1-4 Combustion rate of mixed pulverized coal for injection, %

[0078]

[0079] According to the calculation results, for an effective furnace capacity of 300m 3 When the blast furnace is set at a lower blast temperature of 1000°C, the combustion rate of the mixed coal powder sprayed into the furnace is 90.56%, that is, under the coal type combination and the set blast temperature in this embodiment, the combustion rate of the mixed coal powder is lower than the control index of 92.50%, indicating that the combustion rate of the mixed coal powder in the furnace is low. Measures such as increasing the proportion of bituminous coal or increasing the blast temperature should be taken to increase the combustion rate of the mixed coal powder in the furnace, thereby improving the operation effect of the blast furnace and realizing low-consumption and high-efficiency production.

[0080] [Example 2]

[0081] This example uses a steel plant with an effective furnace capacity of 1800m 3 Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 2-1.

[0082] Table 2-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0083]

[0084]

[0085] The composition of the mixed coal powder for blast furnace injection is detailed in Table 2-2.

[0086] Table 2-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0087]

[0088] For details on the blast furnace set blast temperature, please see Table 2-3.

[0089] Table 2-3 Blast furnace set blast temperature, ℃

[0090]

[0091] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 2-4.

[0092] Table 2-4 Combustion rate of mixed pulverized coal for injection, %

[0093]

[0094] According to the calculation results, for an effective furnace capacity of 1800m 3 When the blast furnace is set at a lower blast temperature of 1050°C, the combustion rate of the mixed coal powder sprayed into the furnace is 91.12%, that is, under the coal type combination and the set blast temperature in this embodiment, the combustion rate of the mixed coal powder in the furnace is lower than the control index of 92.50%, indicating that the combustion rate of the mixed coal powder in the furnace is low. Measures such as increasing the proportion of bituminous coal or increasing the blast temperature should be taken to increase the combustion rate of the mixed coal powder in the furnace, thereby improving the operation effect of the blast furnace and realizing low-consumption and high-efficiency production.

[0095] [Example 3]

[0096] This example uses a steel plant with an effective furnace capacity of 2580m 3 Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 3-1.

[0097] Table 3-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0098]

[0099] The composition of the mixed coal powder for blast furnace injection is detailed in Table 3-2.

[0100] Table 3-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0101]

[0102] For details on the set blast temperature of the blast furnace, please see Table 3-3.

[0103] Table 3-3 Blast furnace set blast temperature, ℃

[0104]

[0105] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 3-4.

[0106] Table 3-4 Combustion rate of mixed pulverized coal for injection, %

[0107]

[0108] According to the calculation results, for an effective furnace capacity of 2580m 3 When the blast temperature of the blast furnace is set at 1100°C, the combustion rate of the mixed coal powder sprayed into the furnace is 90.56%, that is, under the coal type combination and the set blast temperature in this embodiment, the combustion rate of the mixed coal powder in the furnace is lower than the control index of 92.50%, indicating that the combustion rate of the mixed coal powder in the furnace is low. Measures such as increasing the proportion of bituminous coal or increasing the blast temperature should be taken to increase the combustion rate of the mixed coal powder in the furnace, thereby improving the operation effect of the blast furnace and realizing low-consumption and high-efficiency production.

[0109] [Example 4]

[0110] This example uses a steel plant with an effective furnace capacity of 3200m 3 Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 4-1.

[0111] Table 4-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0112]

[0113] The composition of the mixed coal powder for blast furnace injection is detailed in Table 4-2.

[0114] Table 4-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0115]

[0116] For details on the set blast temperature of the blast furnace, please see Table 4-3.

[0117] Table 4-3 Blast furnace set blast temperature, ℃

[0118]

[0119] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 4-4.

[0120] Table 4-4 Combustion rate of mixed pulverized coal for injection, %

[0121]

[0122] According to the calculation results, for an effective furnace capacity of 3200m 3 When the blast temperature of the blast furnace is set at 1200°C, the combustion rate of the mixed coal powder sprayed into the furnace is 93.29%, that is, under the coal type combination and the set blast temperature in this embodiment, the combustion rate of the mixed coal powder in the furnace exceeds the control index of 92.50%, indicating that this combination scheme is a more reasonable coal blending structure, which is beneficial to the low-consumption and high-efficiency production of the blast furnace.

[0123] [Example 5]

[0124] This example uses a steel plant with an effective furnace capacity of 4038m 3 Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 5-1.

[0125] Table 5-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0126]

[0127] The composition of the mixed coal powder for blast furnace injection is detailed in Table 5-2.

[0128] Table 5-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0129]

[0130] For details on the set blast temperature of the blast furnace, please see Table 5-3.

[0131] Table 5-3 Blast furnace set blast temperature, ℃

[0132]

[0133] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 5-4.

[0134] Table 5-4 Combustion rate of mixed pulverized coal for injection, %

[0135]

[0136] According to the calculation results, for an effective furnace capacity of 4038m 3When the blast furnace is set at a higher blast temperature of 1250°C, the combustion rate of the mixed pulverized coal sprayed into the furnace is 93.98%, that is, under the coal type combination and set blast temperature of this embodiment, the combustion rate of the mixed pulverized coal in the furnace exceeds the control index of 92.50%, indicating that this combination scheme is a more reasonable coal blending structure, which is beneficial to the low-consumption and high-efficiency production of the blast furnace.

[0137] [Example 6]

[0138] This example uses a steel plant with an effective furnace capacity of 5500m 3 Taking pulverized coal injection in blast furnace as an example, the composition ratio of mixed pulverized coal for blast furnace injection is shown in Table 6-1.

[0139] Table 6-1 Composition ratio of mixed pulverized coal for blast furnace injection

[0140]

[0141] The composition of the mixed coal powder for blast furnace injection is detailed in Table 6-2.

[0142] Table 6-2 Composition of mixed pulverized coal for blast furnace injection, wt%

[0143]

[0144] For details on the set blast temperature of the blast furnace, please see Table 6-3.

[0145] Table 6-3 Blast furnace set blast temperature, ℃

[0146]

[0147] Formula 1 is used to calculate the combustion rate of the mixed pulverized coal injected into the blast furnace at the set blast temperature. The calculation results are shown in Table 6-4.

[0148] Table 6-4 Combustion rate of mixed pulverized coal for injection, %

[0149]

[0150] According to the calculation results, for an effective furnace capacity of 5500m 3 When the blast temperature of the blast furnace is set at 1300°C, the combustion rate of the mixed pulverized coal sprayed into the furnace is 94.43%, that is, under the coal type combination and the set blast temperature in this embodiment, the combustion rate of the mixed pulverized coal in the furnace exceeds the control index of 92.50%, indicating that this combination scheme is a more reasonable coal blending structure, which is beneficial to the low-consumption and high-efficiency production of the blast furnace.

[0151] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures, characterized in that: The following steps are involved: 1) Determine the evaluation parameters related to the combustion rate of the mixed coal powder, including fixed carbon content, volatile matter content, ash content and sulfur content; 2) According to the historical data recorded in the blast furnace production and operation database, the contribution value of each evaluation parameter to the combustion rate calculation is set; 3) According to the historical data recorded in the blast furnace production operation database, the contribution value of the blast temperature to the mixed coal powder combustion rate is set; 4) According to the historical data recorded in the blast furnace production operation database, the correlation coefficients of the blast temperature and the evaluation parameters for the mixed coal powder combustion rate are set respectively; 5) Establish a formula for calculating the combustion rate of mixed pulverized coal composed of blast temperature and evaluation parameters, and set the error compensation coefficient based on the historical data recorded in the blast furnace production and operation database; The calculation formula for the combustion rate of mixed pulverized coal at different blast temperatures is: Where, BR is the combustion rate of mixed pulverized coal at different blast temperatures, %; F C --Fixed carbon content in mixed coal powder, %; V--volatile matter content in mixed coal powder, %; A--ash content in mixed coal powder, %; S--Sulfur content in mixed coal powder, %; K--error compensation coefficient, which is a constant and takes a value of 1.02%, %; A1--Correlation coefficient of blast temperature, which is a constant and takes the value as 0.23, % / ℃; A2--Correlation coefficient of evaluation parameters, which is a constant and takes a value of 0.24%; 6) The specific values ​​of each evaluation parameter and the set blast temperature value are respectively determined and substituted into Formula 1 to obtain the predicted value of the combustion rate of the mixed coal powder at the corresponding blast temperature.

2. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 1, characterized in that: The mixed coal powder is composed of two or more different types of coal powder, and the different types of coal powder include anthracite, lean coal, lean coal, bituminous coal, lignite and alternative coal.

3. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 2, characterized in that: The alternative coal types include one or more of lignite, CDQ powder, upgraded coal, biomass fuel, and blast furnace dust ash.

4. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 3, characterized in that: The biomass fuel includes one or more of charcoal, activated carbon, straw, fruit wood shell and rice husk.

5. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 3, characterized in that: The blast furnace dust removal ash includes one or more of the following: ore coke trough dust removal ash, furnace top dust removal ash, and furnace front dust removal ash.

6. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 1, characterized in that: The blast temperature ranges from 700°C to 1350°C.

7. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 1, characterized in that: In terms of weight percentage, the fixed carbon content ranges from 50% to 88%, the volatile matter content ranges from 6% to 40%, the ash content ranges from 5% to 20%, and the sulfur content ranges from 0.2% to 2.5%.

8. The method for calculating the combustion rate of mixed pulverized coal for injection at different blast temperatures according to claim 1, characterized in that: The control index of the combustion rate of the mixed coal powder is 92.50%. The calculated combustion rate value ≥92.50% is evaluated as meeting the requirements, and the calculated combustion rate value <92.50% is evaluated as not meeting the requirements. For the mixed coal powder that does not meet the requirements, the ingredients are readjusted, bituminous coal is added, or the proportion of bituminous coal in the mixed coal powder is increased.

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