A method for calculating a blast furnace coal coke replacement ratio based on a carbon balance principle

Abstract

The application provides a blast furnace coal coke replacement ratio calculation method based on a carbon balance principle, and belongs to the technical field of blast furnace coal coke replacement ratio calculation; in order to solve the technical problems that the hydrogen utilization rate is estimated by using an experience formula, the coal powder heat consumption is processed by using a fixed coefficient, the coal coke replacement ratio calculation is inaccurate, and the adaptability to different coal types is poor, basic component parameters of the coal powder and the coke are determined, the hydrogen utilization rate is calculated based on the actual material balance of the total hydrogen amount entering the furnace and the hydrogen content in the top gas, the carbon amount saved by hydrogen in the coal participating in reduction is calculated, the carbon amount consumed by the ash in the coal powder and the coke for slagging is calculated, the carbon amount consumed by the coal powder decomposition heat and the physical heat when heated to 1500 DEG C is calculated, the coal coke replacement ratio is calculated by using a theoretical replacement ratio formula according to the carbon balance principle; the application is applied to blast furnace coal coke replacement ratio calculation.

Description

Technical Field

[0001] This invention provides a method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance, belonging to the technical field of blast furnace coal and coke replacement ratio calculation. Background Technology

[0002] Blast furnace ironmaking is the core process of the steel industry. Coke, as the main fuel and reducing agent, not only provides heat and reducing gas to the blast furnace but also plays a crucial role in supporting the furnace charge and maintaining its permeability. However, with increasingly scarce global coking coal resources, continuously rising coke prices, and increasingly stringent environmental requirements, steel companies are facing enormous cost and environmental pressures. Against this backdrop, pulverized coal injection technology has emerged as an effective coke substitute and has become one of the important technologies for modern blast furnace operation.

[0003] The coal-coke replacement ratio is a core indicator for evaluating the effectiveness of pulverized coal injection, defined as the mass of coke that can be replaced by a unit mass of pulverized coal. This parameter directly relates to the economic and technical feasibility of pulverized coal injection and is an important basis for formulating injection strategies, selecting coal blending ratios, and optimizing operating parameters. However, due to the complexity of the internal reaction processes in blast furnaces and the numerous factors affecting the coal-coke replacement ratio, accurate calculation and prediction of the replacement ratio has always been a technical challenge for the industry.

[0004] Currently, domestic research on coal-coke replacement ratio mainly employs simplified calculation methods based on empirical formulas. Existing technologies, when calculating hydrogen utilization, typically rely on empirical regression formulas related to carbon monoxide utilization, rather than basing it on the actual mass balance of hydrogen. This can easily lead to significant deviations under different furnace conditions and high-hydrogen coal injection conditions, making it difficult to accurately characterize the actual reduction contribution of hydrogen. Furthermore, when calculating the carbon consumed by the decomposition heat and heating physical heat of pulverized coal, existing methods often use fixed empirical coefficients for simplification, ignoring the differences in volatile matter content and thermochemical properties among different coal types. This results in limited calculation accuracy, making it impossible to accurately distinguish the true replacement capacity of various coal types and failing to meet the demands of modern blast furnace refined and low-carbon smelting. Summary of the Invention

[0005] To address the technical problems existing in the background art, the present invention provides a method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance, comprising the following calculation steps:

[0006] S1, determining the basic component parameters of pulverized coal and coke;

[0007] S2, based on the actual material balance between the total amount of hydrogen entering the furnace and the hydrogen content in the top gas, calculate the hydrogen utilization rate, and accordingly calculate the amount of carbon saved by hydrogen in the coal participating in the reduction.

[0008] S3, calculate the amount of carbon consumed in the ash slag formation of pulverized coal and coke;

[0009] S4, calculate the amount of carbon consumed by the heat of coal decomposition and the physical heat when heated to 1500℃;

[0010] S5. Based on the principle of carbon balance, the coal-coke replacement ratio is calculated using the theoretical replacement ratio formula.

[0011] In step S1, the basic component parameters include:

[0012] Fixed carbon mass fraction w(C) in pulverized coal coal Hydrogen mass fraction w(H) coal Ash content mass fraction A coal The mass fraction of SiO2 in ash, w(SiO2). coal And the mass fraction of fixed carbon in coke, w(C). coke Hydrogen mass fraction w(H) coke Ash content mass fraction A coke The mass fraction of SiO2 in ash, w(SiO2). coke .

[0013] In step S5, the theoretical replacement ratio formula is:

[0014] ;

[0015] In the formula, Coal-coke replacement ratio;

[0016] w(C) coal The fixed carbon mass fraction in pulverized coal;

[0017] w(C) H The amount of carbon saved by the reduction of hydrogen in coal;

[0018] w(C) coal, ash The amount of carbon consumed in the slag formation of pulverized coal ash;

[0019] w(C) l The amount of carbon consumed for the heat of coal decomposition and the physical heat of heating to 1500℃;

[0020] w(C) coke The mass fraction of fixed carbon in coke;

[0021] w(C) coke, ash This refers to the amount of carbon consumed in the slag formation process for coke ash.

[0022] The amount of carbon (w(C)) saved by the reduction of hydrogen in the coal. H The calculation formula is:

[0023] ;

[0024] In the formula, Hydrogen utilization rate;

[0025] The molar ratio of carbon to hydrogen;

[0026] The heat is replaced by hydrogen participating in direct reduction;

[0027] This represents the total heat released per unit mass of carbon during combustion at the vent.

[0028] The hydrogen utilization rate The calculation formula is:

[0029] ;

[0030] In the formula, The total amount of hydrogen gas supplied per unit of pig iron entering the furnace;

[0031] This refers to the hydrogen content in the top gas of a pig iron furnace.

[0032] The amount of carbon w(C) consumed in the ash formation of the pulverized coal. coal, ash The calculation formula is:

[0033] ;

[0034] The amount of carbon w(C) consumed in the ash formation of the coke. coke, ash The calculation formula is:

[0035] ;

[0036] In the formula, R is the binary basicity of the slag;

[0037] The enthalpy of slag;

[0038] This represents the total heat released when a unit mass of carbon burns at the air vent.

[0039] A coal The mass fraction of ash in pulverized coal;

[0040] w(SiO2) coal This represents the mass fraction of SiO2 in pulverized coal ash.

[0041] A coke This refers to the mass fraction of ash in coke.

[0042] w(SiO2) coke This represents the mass fraction of SiO2 in the coke ash.

[0043] The total heat released when a unit mass of carbon is burned at the vent The calculation formula is:

[0044] ;

[0045] In the formula, The air volume required for 1 kg of carbon to burn in the vortex swirl zone;

[0046] For the enthalpy of the blower;

[0047] For wind temperature;

[0048] The heat released by the incomplete combustion of 1 kg of carbon;

[0049] The physical heat of 1 kg of carbon in coke when heated to 1500℃.

[0050] The amount of carbon consumed by the heat of coal decomposition and the physical heat of heating to 1500°C, w(C). l The calculation formula is:

[0051] ;

[0052] In the formula, The heat of decomposition per unit of pulverized coal;

[0053] The physical heat consumed when a unit of pulverized coal is heated to 1500℃;

[0054] This represents the total heat released per unit mass of carbon during combustion at the vent.

[0055] The advantages of this invention compared to existing technologies are as follows: This invention provides a method for calculating the blast furnace coal-coke replacement ratio based on the carbon balance principle. By measuring the basic component parameters of pulverized coal and coke, and based on the actual material balance of the total hydrogen input and the hydrogen content in the top gas, the hydrogen utilization rate is calculated. Based on this, the amount of carbon saved by hydrogen in the coal participating in reduction is calculated, as is the amount of carbon consumed by ash slagging in pulverized coal and coke, and the amount of carbon consumed by the heat of pulverized coal decomposition and the physical heat of heating to 1500℃. According to the carbon balance principle, the coal-coke replacement ratio is calculated using a theoretical replacement ratio formula. This invention establishes a calculation model based on a strict carbon balance principle and accurately calculates the hydrogen utilization rate using actual material balance, replacing the traditional estimation method relying on empirical formulas, significantly improving the accuracy of the assessment of hydrogen reduction contribution. Simultaneously, by accurately calculating the heat of pulverized coal decomposition and the physical heat of heating, fixed empirical coefficients are eliminated, enabling differentiated characterization of the thermochemical properties of different coal types. This method constructs a complete, closed-loop carbon calculation system with greater versatility and accuracy. It can provide reliable quantitative basis for the selection of blast furnace injection coal and the optimization of operating parameters, thereby effectively supporting cost reduction, efficiency improvement, and low-carbon production in the blast furnace ironmaking process. Attached Figure Description

[0056] The present invention will be further described below with reference to the accompanying drawings:

[0057] Figure 1 This is a flowchart illustrating the steps of the blast furnace coal-coke replacement ratio calculation method based on the carbon balance principle of this invention. Detailed Implementation

[0058] like Figure 1 As shown, this invention addresses the technical problems in existing technologies where the calculation of the coal-coke replacement ratio is inaccurate and lacks adaptability to different coal types due to the use of empirical formulas to estimate hydrogen utilization and the use of fixed coefficients to handle pulverized coal heat consumption. It provides a method for calculating the blast furnace coal-coke replacement ratio based on the principle of carbon balance. By measuring the basic component parameters of pulverized coal and coke, and based on the actual material balance between the total hydrogen input and the hydrogen content in the top gas, the hydrogen utilization rate is calculated. Based on this, the amount of carbon saved by hydrogen in the coal during reduction is calculated, as is the amount of carbon consumed by ash slagging in pulverized coal and coke, and the heat of coal decomposition and heating to 150°C are also calculated. The amount of carbon consumed by the physical heat at 0℃ is calculated using the theoretical replacement ratio formula based on the carbon balance principle. This invention significantly improves the accuracy of assessing the contribution of hydrogen reduction by establishing a calculation model based on the carbon balance principle, replacing the traditional estimation method that relies on empirical formulas. This achieves the technical effects of significantly improving the accuracy of replacement ratio calculation, enhancing the universality of the method for different coal types, and providing a reliable quantitative basis for blast furnace injection optimization and coal blending decisions. At the same time, by accurately calculating the heat of coal decomposition and the physical heat of heating, and abandoning fixed empirical coefficients, it realizes the differentiated characterization of the thermochemical properties of different coal types.

[0059] like Figure 1 As shown, this embodiment of the invention provides a method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance, including the following steps:

[0060] S1, determining the basic component parameters of pulverized coal and coke;

[0061] S2, based on the actual material balance between the total amount of hydrogen entering the furnace and the hydrogen content in the top gas, calculate the hydrogen utilization rate, and accordingly calculate the amount of carbon saved by hydrogen in the coal participating in the reduction.

[0062] S3, calculate the amount of carbon consumed in the ash slag formation of pulverized coal and coke;

[0063] S4, calculate the amount of carbon consumed by the heat of coal decomposition and the physical heat when heated to 1500℃;

[0064] S5. Based on the principle of carbon balance, the coal-coke replacement ratio is calculated using the theoretical replacement ratio formula.

[0065] In the technical solution of this invention embodiment, an industrial analyzer and an X-ray fluorescence spectrometer are used to determine the basic component parameters of pulverized coal and coke, including the fixed carbon mass fraction w(C) in the pulverized coal. coal Hydrogen mass fraction w(H) coal Ash content mass fraction A coal The mass fraction of SiO2 in ash, w(SiO2). coal And the mass fraction of fixed carbon in coke, w(C). coke Hydrogen mass fraction w(H) coke Ash content mass fraction A coke The mass fraction of SiO2 in ash, w(SiO2). coke .

[0066] Furthermore, in some embodiments, the theoretical replacement ratio formula is:

[0067] ;

[0068] In the formula, Coal-coke replacement ratio;

[0069] w(C) coal The fixed carbon mass fraction in pulverized coal;

[0070] w(C) H The amount of carbon saved by the reduction of hydrogen in coal;

[0071] w(C) coal, ash The amount of carbon consumed in the slag formation of pulverized coal ash;

[0072] w(C) lThe amount of carbon consumed for the heat of coal decomposition and the physical heat of heating to 1500℃;

[0073] w(C) coke The mass fraction of fixed carbon in coke;

[0074] w(C) coke, ash This refers to the amount of carbon consumed in the slag formation process for coke ash.

[0075] In the technical solution of this invention, a complete closed-loop calculation model based on the principle of carbon balance is established by comprehensively considering coal composition, hydrogen carbon-saving mechanism, ash slag-forming heat consumption, and physical heat consumption. This method is not only applicable to the evaluation of conventional coal types, but also to the evaluation of the replacement effect of new fuels such as high-hydrogen coal and biochar. Due to the significant improvement in calculation accuracy, this method can provide steel enterprises with a more economically valuable basis for coal selection. By accurately predicting the actual replacement ratio of coal types with different cost-effectiveness, enterprises can optimize the coal blending structure and avoid fuel ratio fluctuations caused by overestimation of the replacement ratio, thereby minimizing fuel costs and maximizing economic benefits while ensuring smooth blast furnace operation.

[0076] Furthermore, in some embodiments, the amount of carbon saved w(C) by the reduction of hydrogen in coal is further... H The calculation formula is:

[0077] ;

[0078] In the formula, Hydrogen utilization rate;

[0079] The molar ratio of carbon to hydrogen;

[0080] The heat is replaced by hydrogen participating in direct reduction;

[0081] This represents the total heat released when a unit mass of carbon burns at the air vent.

[0082] Hydrogen utilization rate The calculation formula is:

[0083] ;

[0084] In the formula, The total amount of hydrogen gas supplied per unit of pig iron entering the furnace;

[0085] This refers to the hydrogen content in the top gas of a pig iron furnace.

[0086] In the technical solution of this invention, the calculation of hydrogen utilization rate is more accurate, overcoming the limitations of empirical formulas. Existing technologies typically employ empirical regression formulas based on CO utilization rate (…). Estimating hydrogen utilization rate using traditional methods ignores the fundamental differences in reduction kinetics between hydrogen and CO. This invention, based on a rigorous hydrogen mass balance principle, determines the actual hydrogen utilization rate by calculating the difference between the total hydrogen input to the furnace and the hydrogen content in the top gas. This method does not rely on empirical parameters specific to any particular furnace type, accurately reflects the hydrogen reduction efficiency under current smelting conditions, and significantly improves the accuracy of the calculation results. This is particularly beneficial for hydrogen-rich smelting or high-volatile bituminous coal injection conditions, eliminating the significant biases introduced by traditional empirical formulas.

[0087] Specifically, the following calculation formula is used:

[0088] ;

[0089] ;

[0090] ;

[0091] ;

[0092] in, Here is the molar mass of hydrogen. Here is the molar mass of hydrogen. The hydrogen content per unit of pig iron fed into the furnace; ; The amount of hydrogen introduced by the humidity of the blower air. is the relative molecular mass of hydrogen gas. This is the relative molecular mass of water; The absolute humidity of the blower; The air volume consumed per unit of pig iron; The amount of top gas produced per unit of pig iron; This represents the volume fraction of hydrogen in the top gas. is the molar mass of hydrogen gas; This represents the volume of 1 mol of gas under standard conditions.

[0093] Furthermore, in some embodiments, the amount of carbon w(C) consumed in the ash slag formation of pulverized coal is... coal, ash The calculation formula is:

[0094] ;

[0095] The amount of carbon consumed in ash formation from coke, w(C). coke, ash The calculation formula is:

[0096] ;

[0097] In the formula, R is the binary basicity of the slag;

[0098] The enthalpy of slag;

[0099] This represents the total heat released when a unit mass of carbon burns at the air vent.

[0100] A coal The mass fraction of ash in pulverized coal;

[0101] w(SiO2) coal This represents the mass fraction of SiO2 in pulverized coal ash.

[0102] A coke This refers to the mass fraction of ash in coke.

[0103] w(SiO2) coke This represents the mass fraction of SiO2 in the coke ash.

[0104] Furthermore, the total heat released by a unit mass of carbon burning at the vent. The calculation formula is:

[0105] ;

[0106] In the formula, The air volume required for 1 kg of carbon to burn in the vortex swirl zone;

[0107] For the enthalpy of the blower;

[0108] For wind temperature;

[0109] The heat released by the incomplete combustion of 1 kg of carbon;

[0110] The physical heat of 1 kg of carbon in coke when heated to 1500℃.

[0111] The amount of carbon consumed by the heat of coal decomposition and the physical heat of heating to 1500℃, w(C). l The calculation formula is:

[0112] ;

[0113] In the formula, The heat of decomposition per unit of pulverized coal;

[0114] The physical heat consumed when a unit of pulverized coal is heated to 1500℃;

[0115] This represents the total heat released per unit mass of carbon during combustion at the vent.

[0116] In the technical solution of this invention, the influence of the thermochemical properties of pulverized coal is precisely quantified, thus eliminating the need for fixed coefficient estimation. Existing technologies often use fixed empirical coefficients (such as 46%) for simplification when calculating the carbon content consumed by the heat of pulverized coal decomposition and physical heat of heating. This invention introduces specific thermodynamic calculations of the heat of pulverized coal decomposition and the physical heat of heating, accurately distinguishing the differences in decomposition endothermics caused by different coal types (such as anthracite, lean coal, and gas coal) due to differences in volatile matter content and molecular structure. By incorporating these into precise calculations, the subtle influence of coal type changes on the replacement ratio can be keenly captured, solving the problem that existing technologies cannot accurately assess the true replacement capacity of high-volatile coal types.

[0117] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0118] Embodiments of the present invention provide a method for calculating the blast furnace coal-coke replacement ratio based on the principle of carbon balance, taking a blast furnace of 2650m³ as an example. 3 The actual production data of pulverized coal injection in blast furnace will be used to illustrate this, specifically including the following steps:

[0119] S1, Determine the basic component parameters of pulverized coal and coke; determine the dry basis fixed carbon of pulverized coal and coke using an industrial analyzer and X-ray fluorescence spectrometer. Hydrogen content The results of ash content A and the mass fraction of SiO2 in the ash are shown in Table 1:

[0120] Table 1. Composition and parameters of raw materials and fuels

[0121]

[0122] S2, based on the actual material balance between the total amount of hydrogen entering the furnace and the hydrogen content in the top gas, calculate the hydrogen utilization rate, and accordingly calculate the amount of carbon saved by hydrogen in the coal participating in the reduction.

[0123] Hydrogen content of raw materials fed into the furnace:

[0124]

[0125] =150kg / t×3.0%+350kg / t×0.4%+1600kg / t×0.1%=7.5kg / t;

[0126] in, This represents the mass fraction of hydrogen in the ore.

[0127] The amount of hydrogen introduced by the humidity of the blower air:

[0128]

[0129] =1200m 3 / t×0.015kg / m 3 ×2 / 18=2kg / t;

[0130] Among them, the absolute humidity of the blast furnace operating parameters is f=0.015kg / m³. 3 Air volume consumed per unit of pig iron =1200m 3 The relative molecular mass of hydrogen =2, the relative molecular mass of water =18;

[0131] Total hydrogen input to the furnace:

[0132]

[0133] =7.5kg / t + 2kg / t = 9.5kg / t;

[0134] Since the reduction reaction in the blast furnace consumes and produces H2 molecules, and the analysis of the top gas measures the concentration of H2 molecules, the mass of hydrogen in the feed material is converted into the equivalent mass of H2 molecules for balance calculations. The mass of hydrogen gas fed into the furnace is as follows:

[0135]

[0136] =9.5kg / t×(2g / mol / (2×1g / mol))=9.5kg / t;

[0137] Hydrogen content in the top gas:

[0138]

[0139] =1700m 3 / t×3%×(2g / mol / 22.4L / mol)=4.55kg / t;

[0140] The amount of furnace top gas produced per unit of pig iron is calculated using a flow meter. =1700m 3 / t, the volume fraction of hydrogen in the top gas was determined using an infrared analyzer. =3%, the molar mass of hydrogen =2g / mol, volume of 1 mol of gas under standard conditions =22.4 L / mol;

[0141] Hydrogen utilization rate:

[0142]

[0143] = (9.5kg / t-4.55kg / t) / 9.5kg / t=0.52;

[0144] The total heat released when a unit mass of carbon burns at the vent:

[0145]

[0146] =4.29m 3 / kg×1.5kJ / (m 3 ·℃)×1200℃+9794kJ / kg+2758kJ / kg=20274kJ / kg;

[0147] The calculations show that the air volume required for 1 kg of carbon to burn in the vortex zone is [not specified]. =4.29m 3 / kg, enthalpy of forced air Take 1.5 kJ / (m 3 ·℃), wind temperature Take the heat released by the incomplete combustion of 1 kg of carbon at 1200℃. Take 9794 kJ / kg as the physical heat of 1 kg of carbon in coke when heated to 1500℃. Take 2758 kJ / kg;

[0148] The amount of carbon saved by hydrogen in coal during reduction:

[0149]

[0150] =3%×0.52×(12 / 2+62222kJ / kg / 20274kJ / kg)=14.15%;

[0151] Among them, the molar ratio of carbon to hydrogen The heat replaced by hydrogen in direct reduction Take 62222 kJ / kg;

[0152] S3, calculate the amount of carbon consumed in the ash slag formation of pulverized coal and coke;

[0153] The amount of carbon consumed in slag formation from pulverized coal ash is:

[0154]

[0155] =10%×(1+45%×1.15)×1883kJ / kg / 20274kJ / kg=1.409%;

[0156] Among them, the binary basicity of the slag R=1.15, and the enthalpy of the slag... Take 1883 kJ / kg;

[0157] The amount of carbon consumed in coke ash slag formation is:

[0158]

[0159] =12%×(1+40%×1.15)×1883kJ / kg / 20274kJ / kg=1.627%;

[0160] S4, calculate the amount of carbon consumed by the heat of coal decomposition and the physical heat when heated to 1500℃;

[0161] The amount of carbon consumed by the heat of coal decomposition and the physical heat of heating to 1500℃:

[0162]

[0163] = (240kcal / kg+480kcal / kg) / 20274kJ / kg=14.86%;

[0164] In this embodiment, the pulverized coal used is anthracite, and the heat of decomposition of a unit of anthracite pulverized coal is... The physical heat consumed when heating a unit of pulverized coal to 1500℃ is 240 kcal / kg. Take 480 kcal / kg;

[0165] S5. Based on the principle of carbon balance, the coal-coke replacement ratio is calculated using the theoretical replacement ratio formula.

[0166] Coal-coke replacement ratio:

[0167]

[0168] = (75% + 14.15% - 1.409% - 14.86%) / (85% - 1.627%) = 0.898.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance, characterized in that: The calculation steps include the following: S1, determining the basic component parameters of pulverized coal and coke; S2, based on the actual material balance between the total amount of hydrogen entering the furnace and the hydrogen content in the top gas, calculate the hydrogen utilization rate, and accordingly calculate the amount of carbon saved by hydrogen in the coal participating in the reduction. S3, calculate the amount of carbon consumed in the ash slag formation of pulverized coal and coke; S4, calculate the amount of carbon consumed by the heat of coal decomposition and the physical heat when heated to 1500℃; S5. Based on the principle of carbon balance, the coal-coke replacement ratio is calculated using the theoretical replacement ratio formula.

2. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 1, characterized in that: In step S1, the basic component parameters include: Fixed carbon mass fraction w(C) in pulverized coal coal Hydrogen mass fraction w(H) coal Ash content mass fraction A coal The mass fraction of SiO2 in ash, w(SiO2). coal And the mass fraction of fixed carbon in coke, w(C). coke Hydrogen mass fraction w(H) coke Ash content mass fraction A coke The mass fraction of SiO2 in ash, w(SiO2). coke .

3. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 2, characterized in that: In step S5, the theoretical replacement ratio formula is: ； In the formula, Coal-coke replacement ratio; w(C) coal The fixed carbon mass fraction in pulverized coal; w(C) H The amount of carbon saved by the reduction of hydrogen in coal; w(C) coal, ash The amount of carbon consumed in the slag formation of pulverized coal ash; w(C) l The amount of carbon consumed for the heat of coal decomposition and the physical heat of heating to 1500℃; w(C) coke The mass fraction of fixed carbon in coke; w(C) coke, ash This refers to the amount of carbon consumed in the slag formation process for coke ash.

4. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 3, characterized in that: The amount of carbon (w(C)) saved by the reduction of hydrogen in the coal. H The calculation formula is: ； In the formula, Hydrogen utilization rate; The molar ratio of carbon to hydrogen; The heat is replaced by hydrogen participating in direct reduction; This represents the total heat released per unit mass of carbon during combustion at the vent.

5. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 4, characterized in that: The hydrogen utilization rate The calculation formula is: ； In the formula, The total amount of hydrogen gas supplied per unit of pig iron entering the furnace; This refers to the hydrogen content in the top gas of a pig iron furnace.

6. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 3, characterized in that: The amount of carbon w(C) consumed in the ash formation of the pulverized coal. coal, ash The calculation formula is: ； The amount of carbon w(C) consumed in the ash formation of the coke. coke, ash The calculation formula is: ； In the formula, R is the binary basicity of the slag; The enthalpy of slag; This represents the total heat released when a unit mass of carbon burns at the air vent. A coal The mass fraction of ash in pulverized coal; w(SiO2) coal This represents the mass fraction of SiO2 in pulverized coal ash. A coke This refers to the mass fraction of ash in coke. w(SiO2) coke This represents the mass fraction of SiO2 in the coke ash.

7. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 4, characterized in that: The total heat released when a unit mass of carbon is burned at the vent The calculation formula is: ； In the formula, The air volume required for 1 kg of carbon to burn in the vortex swirl zone; For the enthalpy of the blower; For wind temperature; The heat released by the incomplete combustion of 1 kg of carbon; The physical heat of 1 kg of carbon in coke when heated to 1500℃.

8. The method for calculating the replacement ratio of blast furnace coal and coke based on the principle of carbon balance according to claim 3, characterized in that: The amount of carbon consumed by the heat of coal decomposition and the physical heat of heating to 1500°C, w(C). l The calculation formula is: ； In the formula, The heat of decomposition per unit of pulverized coal; The physical heat consumed when a unit of pulverized coal is heated to 1500℃; This represents the total heat released per unit mass of carbon during combustion at the vent.

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