A blast furnace coal injection pulverized coal comprehensive performance evaluation method and system based on combustion and reaction kinetics

Abstract

The present application relates to the technical field of steel metallurgical process optimization, and particularly relates to a blast furnace coal injection coal powder comprehensive performance evaluation method and system based on combustion and reaction kinetics, comprising preparing a standard residual carbon sample, performing a combustion experiment and collecting data, calculating the dynamic burnout rate of the blast furnace coal injection coal powder, calculating the reactivity of the residual carbon of the blast furnace coal injection coal powder, calculating the coal ash behavior index for evaluating the harm degree of the coal ash to blast furnace smelting, establishing a model about the dynamic burnout rate, the reactivity of the residual carbon and the coal ash behavior index, and calculating the comprehensive performance index CPI for evaluating the blast furnace coal injection coal powder; the present application obtains key indexes such as the dynamic burnout rate and the residual carbon reactivity by simulating the extreme working condition of the blast furnace tuyere, breaks through the limitation of traditional indexes, deeply fuses and quantifies the physical properties (melting property) of the coal ash and the chemical harm of key chemical components, and forms a comprehensive index capable of directly and comprehensively warning the operation risk of the coal ash to the blast furnace.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgical process optimization technology, and in particular to a method and system for evaluating the comprehensive performance of pulverized coal injected into blast furnaces based on combustion and reaction kinetics. Background Technology

[0002] In the field of pulverized coal injection technology for blast furnaces, existing technological innovations mainly revolve around three directions. First, there are technologies focused on predicting and evaluating combustion performance. These technologies aim to predict or evaluate the combustion effect of pulverized coal. For example, the paper "Prediction Method of Pulverized Coal Combustion Rate for Blast Furnace Injection, MCC Jingcheng Engineering Technology Co., Ltd. 202510131742.6 [P]. 2025-06-03" establishes a prediction model by screening combustion rate characterization parameters of coal samples and utilizing historical data. However, this method relies on historical data and fails to deeply reveal the dynamic combustion process and residual carbon behavior of pulverized coal under extreme conditions within the furnace. Another innovation, "Evaluation Method of the Promoting Combustion Effect of Bituminous Coal on Blast Furnace Blended Coal," calculates the combustion-promoting coefficient P by analyzing gas phase components and residual carbon. However, it focuses on comparing the combustion-promoting effects of blended coals and does not construct a universally applicable comprehensive performance index, nor does it simulate the real environment of the blast furnace.

[0003] Secondly, there are technologies that focus on the control and execution of the pulverized coal injection process. These technologies do not concern themselves with the quality of the pulverized coal itself, but rather focus on how to stably and accurately feed any pulverized coal into the blast furnace. For example, existing patents calculate the optimal pulverized coal injection rate based on the target carbon ratio, the silicon content of the molten iron, and the actual output, focusing on furnace condition feedback and adjustment after the coal enters the furnace; they consider changes in pulverized coal properties through adaptive updates of model parameters to stabilize the injection rate; and they establish mathematical models to correct the weight of the injection flask, aiming to improve injection accuracy. These technologies are all important guarantees for achieving efficient injection, but they belong to the process control level and do not involve the prediction and optimization of pulverized coal performance before it enters the furnace.

[0004] Another technology involves altering the properties of pulverized coal through additives. This approach focuses on "modifying the object" rather than "evaluating the object." For example, multifunctional additives for pulverized coal injected into blast furnaces, developed by relevant institutions, actively improve the combustion performance of pulverized coal by adding external substances such as catalysts and oxidants. This is an effective improvement process, but it falls under the category of performance enhancement, not a system for evaluating the inherent properties of pulverized coal. Summary of the Invention

[0005] This invention provides a method and system for evaluating the comprehensive performance of pulverized coal injected into blast furnaces based on combustion and reaction kinetics. By simulating extreme working conditions at the blast furnace tuyeres, it obtains key indicators such as dynamic burnout rate and residual carbon reactivity, and constructs a comprehensive performance index (CPI). This invention fills a gap in existing technologies and achieves a leap from "static component analysis" to "dynamic performance prediction," demonstrating its unique innovative value and integration potential.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A comprehensive performance evaluation method for pulverized coal injection in blast furnaces based on combustion and reaction kinetics includes the following steps: S1. Prepare standard residual carbon samples, conduct combustion experiments and collect data; S2. Calculate the dynamic burnout rate of pulverized coal injected into the blast furnace; S3. Calculate the reactivity of residual carbon in pulverized coal injected into the blast furnace. S4. Calculate the coal ash behavior index, which is used to evaluate the degree of harm of coal ash to blast furnace smelting. S5. Establish a model for dynamic burnout rate, residual carbon reactivity, and ash behavior index, and calculate the comprehensive performance index (CPI) for evaluating pulverized coal injection in blast furnaces: CPI = A × Dynamic burnout rate + B × Residual carbon reactivity index - C × Coal ash behavior index; Wherein, CPI is the comprehensive performance index of pulverized coal injected into blast furnace; A is the dynamic burnout rate weighting coefficient, with a value range of 0.4 to 0.6; B is the weighting coefficient of residual carbon reactivity index, with a value range of 0.3 to 0.5; C is the weighting coefficient of coal ash toxicity index, with a value range of 0.1 to 0.63; and A+B+C=1, the weighting coefficients A, B, and C are obtained through industrial data regression analysis.

[0007] Furthermore, step 1 specifically includes the following steps: S1.1 The coal powder sample to be tested is dried, ground and sieved, and then sent into a high-temperature tube furnace; S1.2 Set the experimental parameters of the high-temperature tubular furnace to simulate the extreme conditions in the blast furnace tuyeres. Simultaneously start the infrared gas analyzer to perform online gas analysis and record the flue gas concentrations of O2, CO, and CO2 in real time. S1.3 Collect unburned carbon residue.

[0008] Furthermore, the experimental parameters are as follows: preheated air is introduced into the high-temperature tubular furnace, the temperature of the constant temperature zone inside the furnace is controlled at 1300-1500℃, the residence time of pulverized coal in the constant temperature zone inside the furnace is controlled within 50-500ms, the preheated air temperature is selected as 850-950℃, the pulverized coal feeding rate is 0.2-0.8g / min, and the carrier gas flow rate N2 is 0.5-1.0L / min.

[0009] Furthermore, step S2 employs a dual-method parallel calculation of the burnout rate; Gas analysis method for calculating burnout rate DBR1: DBR1 = (M Cgas / M Cin )×100%; Carbon balance method for calculating burnout rate DBR2: DBR2 = [1 - (M residual ×C residual ) / (M coal ×C coal )]×100%; Among them, M Cgas M is the mass flow rate of carbon, in kg / h. Cin M is the carbon feed rate, in kg / h. residual The mass of collected residual carbon is expressed in kg; C residual M represents the carbon mass content in the collected residual carbon. coal Initial coal powder mass, unit: kg; C coal This represents the initial carbon mass content in the pulverized coal. Result verification and output; Calculate the absolute difference ΔDBR = |DBR1 - DBR2|; When ΔDBR≤3%, the test is considered valid, and the final dynamic burnout rate DBR=(DBR1+DBR2) / 2; If ΔDBR > 3%, the test is deemed invalid and the system's sealing, sample representativeness, or measuring instruments must be checked before the test is repeated.

[0010] Furthermore, step S3 specifically includes the following steps: (1) Gasification reaction test: The prepared standard carbon residue sample is placed in a thermogravimetric analyzer and heated from room temperature to 1100-1500℃ at a heating rate of 10-20℃ / min under a 100% CO2 atmosphere, or the standard carbon residue sample is reacted with CO2 under a constant temperature condition of 1100-1300℃. (2) Reactivity Calculation: The mass change curve of the sample during the reaction process is recorded in real time. Based on this curve, the gasification reactivity index (RCRI) of residual carbon is calculated using the following formula: RCRI=(0.5 / )×100%; in, The RCRI value represents the time required for the residual carbon sample to reach a conversion rate of 50%. The higher the RCRI value, the higher the gasification reactivity of the residual carbon.

[0011] Furthermore, the calculation is used to evaluate the degree of harm of coal ash to blast furnace smelting, specifically the coal ash behavior index: HICA=[w1×(K2O+Na2O)+w2×Fe2O3]×f(ST); Wherein, HICA is the toxicity index of coal ash, K2O is the mass percentage of K2O component in coal ash, Na2O is the mass percentage of Na2O component in coal ash, Fe2O3 is the mass percentage of Fe2O3 component in coal ash, and w1, w 2分别 The weighting coefficients of (K2O+Na2O) and Fe2O3 are given, and w1+w2=1 and w1>w2. ST is the softening temperature of coal ash, and f(ST) is the temperature correction function. f(ST) = A / ST; Where A is a constant of the temperature correction function, with a value ranging from 1000 to 1500.

[0012] Furthermore, the weighting coefficient w1 ranges from 0.5 to 0.8, and the weighting coefficient w2 ranges from 0.2 to 0.5.

[0013] Furthermore, the weighting coefficient w1 ranges from 0.6 to 0.7, and the weighting coefficient w2 ranges from 0.3 to 0.4.

[0014] A comprehensive performance evaluation system for pulverized coal injection in blast furnaces based on combustion and reaction kinetics includes: Residual carbon preparation unit: used to prepare standardized residual carbon samples; the residual carbon preparation unit includes a high-temperature tubular furnace, a preheating gas supply system, a feeding device, a sampling system, and a tail gas analysis system. The high-temperature tubular furnace is used to simulate the extreme conditions of the blast furnace tuyeres for experiments. The preheating gas supply system is used to introduce preheating gas at a preset temperature into the high-temperature tubular furnace. The feeding device is used to feed dried, ground, and sieved coal powder into the high-temperature tubular furnace. The sampling system is used to collect incompletely burned residual carbon. The tail gas analysis system is used to detect the composition of the emitted gas. Reactivity testing unit: used to test the reactivity of standard residual carbon samples; the reactivity unit includes a thermogravimetric analyzer, a high-purity CO2 gas source and a temperature control system. The thermogravimetric analyzer is used to measure the relationship between temperature and mass change of the standard residual carbon sample. The high-purity CO2 gas source is used to introduce CO2 into the thermogravimetric analyzer. The temperature control system is used to adjust the temperature of the isothermal reaction zone inside the thermogravimetric analyzer. Data acquisition and processing unit: used to collect data from coal ash, reactivity testing unit, and residual carbon, and to calculate the dynamic burnout rate, residual carbon reactivity, and coal ash behavior index of pulverized coal injected into the blast furnace. The data acquisition and processing unit includes a balance, a gas mass spectrometer, and a computer. The balance is connected to the reactivity testing unit to collect data from the reactivity testing unit. The gas mass spectrometer is used to analyze the composition and content of the gas after the reaction. The computer is used to automatically record data and establish models for dynamic burnout rate, residual carbon reactivity, and coal ash behavior index, and to calculate the comprehensive performance index (CPI) for evaluating pulverized coal injected into the blast furnace.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1) This invention directly measures the burnout rate of pulverized coal through physical experiments simulating blast furnace conditions. It also innovatively adopts a dual-method cross-validation mechanism to ensure the absolute reliability of the results. The invention uses "gas analysis + carbon balance method" to perform parallel execution and mutual verification, ultimately achieving the test of the dynamic burnout rate of injected pulverized coal. The measurement error of the dynamic burnout rate is controlled within 3%, solving the industry pain point of insufficient reliability of traditional single methods. 2) This invention breaks through the limitations of traditional indicators by deeply integrating and quantifying the physical properties (fusibility) of coal ash with the chemical hazards of key chemical components, forming a comprehensive indicator that can directly and comprehensively warn of the risks of coal ash to blast furnace operation. 3) By simulating the rapid combustion environment in the blast furnace tuyeres, a residual carbon sample that is highly similar to the actual situation is prepared. The sample is then placed in a high-temperature CO2 atmosphere in the simulated furnace belly area. Its reactivity is quantified by monitoring its gasification reaction rate. This allows for an accurate and reliable evaluation of the gasification reactivity of residual carbon after pulverized coal combustion under simulated blast furnace belly conditions. 3) This invention simulates extreme working conditions at the blast furnace tuyeres, measures key dynamic indicators that directly reflect the combustion efficiency of pulverized coal and the reactivity of unburned pulverized coal with coke, and constructs a comprehensive performance index (CPI) to guide coal selection and blending. This invention fills the gap in existing technology and achieves a leap from "static composition analysis" to "dynamic performance prediction", demonstrating its unique innovative value and integration potential. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the residual carbon sample preparation unit described in this invention.

[0017] In the diagram: 1. Oxygen inlet pipe; 2. Gas preheating and flow controller a; 3. Heating element; 4. Gas analyzer; 5. Corundum tube; 6. Gas outlet pipe; 7. Storage tank; 8. Feeding vane; 9. Gas preheating and flow controller b; 10. Thermocouple; 11. Pulverized coal injection pipe; 12. Pulverized coal; 13. Nitrogen inlet pipe; 14. Water-cooled collector; 15. Sampler. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: This invention discloses a comprehensive performance evaluation method for pulverized coal injected into blast furnaces based on combustion and reaction kinetics, comprising: S1. Prepare standard residual carbon samples, conduct combustion experiments and collect data; S1.1 The coal powder sample to be tested is dried, ground and sieved to a particle size of 75-150μm, and then fed into a high-temperature tube furnace; S1.2. Preheated air is introduced into the high-temperature tubular furnace. The temperature of the constant temperature zone inside the furnace is controlled at 1300-1500℃. The residence time of pulverized coal in the constant temperature zone is controlled within 50-500ms. The preheated air temperature is selected as 850-950℃. The pulverized coal feeding rate is 0.2-0.8g / min, and the carrier gas flow rate N2 is 0.5-1.0L / min to simulate the extreme conditions of the blast furnace tuyeres. The feeding system is started to inject pulverized coal into the high-temperature tubular furnace. Simultaneously, an infrared gas analyzer is started to perform online gas analysis and record the flue gas concentrations of O2, CO, and CO2 in real time. At the same time, unburned residual carbon is collected through a water-cooled sampling device.

[0019] S2. Calculate the dynamic burnout rate of pulverized coal injected into the blast furnace; Gas analysis method for calculating burnout rate DBR1: DBR1 = (M Cgas / M Cin )×100%; Among them, M Cgas M is the mass flow rate of carbon, in kg / h. Cin The feed rate of carbon is expressed in kg / h. Let the coal powder feed rate be M. coal The unit is kg / h; the mass fraction of carbon in pulverized coal is C. coal Then the carbon feed rate is: M Cin =M coal ×C coal ; In the outlet gas, the concentrations (volume fractions) of CO and CO2 were measured to be [CO] and [CO2], respectively, and the total gas flow rate was measured to be V. gas Unit m 3 / h; The gas flow rate needs to be converted to the volumetric flow rate under standard conditions (0℃, 1 atm). Under standard conditions, the volume of 1 mol of gas is 22.4 L. Therefore, the molar flow rates of CO and CO2 are: n CO =(V gas (×[CO]×1000) / 22.4; n CO2 =(Vgas×[CO2]×1000) / 22.4; The molar flow rate of carbon in the outlet gas is: n Cgas =n CO +n CO2 ; Where, n CO n is the molar flow rate of CO, in mol / h; CO2 n is the molar flow rate of CO2, in mol / h. CgasThe molar flow rate of carbon in the outlet gas, in mol / h; The mass flow rate of carbon is: M Cgas =n Cgas ×m c / 1000; Where, m c m is the molar mass of carbon. c =12g / mol; Carbon balance method for calculating burnout rate DBR2: DBR2 = [1 - (M residual ×C residual ) / (M coal ×C coal )]×100%; Among them, M Cgas M is the mass flow rate of carbon, in kg / h. Cin M is the carbon feed rate, in kg / h. residual The mass of collected residual carbon is expressed in kg; C residual The mass of carbon in the collected residual carbon; the mass of the collected residual carbon and the mass of carbon in the collected residual carbon were determined by an elemental analyzer; M coal Initial coal powder mass, unit: kg; C coal This represents the initial carbon mass content in the pulverized coal. Result verification and output; Calculate the absolute difference ΔDBR = |DBR1 - DBR2|; When ΔDBR≤3%, the test is considered valid, and the final dynamic burnout rate DBR=(DBR1+DBR2) / 2; If ΔDBR > 3%, the test is deemed invalid and the system's sealing, sample representativeness, or measuring instruments must be checked before the test is repeated.

[0020] S3. Calculate the reactivity of residual carbon in pulverized coal injected into the blast furnace. Unburned solid residue is quickly collected at the bottom of the tube furnace using a sampling system. This is the residual carbon sample, which is then ground and sieved to a specific particle size range of 75–150 μm for later use. Gasification reaction test: The prepared standard carbon residue sample is placed in a thermogravimetric analyzer and heated from room temperature to 1500℃ at a heating rate of 10-20℃ / min under a 100% CO2 atmosphere, or it is reacted with CO2 under constant temperature conditions of 1100-1300℃.

[0021] Reactivity calculation; the mass change curve of the sample during the reaction process is recorded in real time. Based on this curve, the gasification reactivity index (RCRI) of residual carbon is calculated using the following formula: RCRI=(0.5 / )×100%; in, The RCRI value represents the time (in minutes) required for the residual carbon sample to reach a conversion rate of 50%. The higher the RCRI value, the higher the gasification reactivity of the residual carbon.

[0022] S4. Calculate the coal ash behavior index, which is used to evaluate the degree of harm of coal ash to blast furnace smelting. The harmfulness of coal ash behavior refers to the degree of harm that coal ash poses to blast furnace smelting. The formula for calculating the harmfulness index of coal ash behavior is as follows: HICA = [w1× (K2O + Na2O) + w2 × Fe2O3] × f(ST); Wherein, HICA is the toxicity index of coal ash; K2O is the mass percentage of K2O component in coal ash, %; Na2O is the mass percentage of Na2O component in coal ash, %; Fe2O3 is the mass percentage of Fe2O3 component in coal ash, %; w1 and w2 are both weighting coefficients, and satisfy w1+w2=1, and w1>w2; ST is the softening temperature of coal ash; and f(ST) is the temperature correction function.

[0023] The weighting coefficient w1 ranges from 0.5 to 0.8, and the weighting coefficient w2 ranges from 0.2 to 0.5. The preferred weighting coefficients w1 are in the range of 0.5 to 0.8, and w2 is in the range of 0.2 to 0.5. The temperature correction function is: f(ST) = A / ST; Where A is a constant of the temperature correction function, with a value ranging from 1000 to 1500, and A preferably has a value of 1300.

[0024] The harmfulness index of coal ash behavior is divided into three risk levels: When the Hazard Index of Coal Ash < 0.5, the degree of hazard of coal ash to blast furnace smelting is judged to be low risk. When the Hazard Index of Coal Ash (HICA) is 0.5 ≤ 1.0, the degree of hazard of coal ash to blast furnace smelting is judged as medium risk. When the Hazard Index of Coal Ash (HICA) is greater than 1.0, the degree of hazard of coal ash to blast furnace smelting is judged to be high risk.

[0025] The procurement, blending, and operational adjustments of pulverized coal for blast furnace injection are guided according to the risk level.

[0026] S5. Establish a model for dynamic burnout rate, residual carbon reactivity, and ash behavior index, and calculate the comprehensive performance index (CPI) for evaluating pulverized coal injection in blast furnaces: CPI = A × Dynamic burnout rate + B × Residual carbon reactivity index - C × Coal ash behavior index; Wherein, CPI is the comprehensive performance index of pulverized coal injected into blast furnace; A is the dynamic burnout rate weighting coefficient, with a value range of 0.4 to 0.6; B is the weighting coefficient of residual carbon reactivity index, with a value range of 0.3 to 0.5; C is the weighting coefficient of coal ash toxicity index, with a value range of 0.1 to 0.63; and A+B+C=1, the weighting coefficients A, B, and C are obtained through industrial data regression analysis.

[0027] The method for determining the weighting coefficients A, B, and C is as follows: Using actual production indicators of blast furnace operation as the target of regression analysis, such as actual coal-coke replacement ratio, fuel ratio, and blast furnace utilization coefficient, a multiple linear regression was established: Key performance indicators = β + A × dynamic burnout rate DBR + B × residual carbon reactivity index RCRI - C × coal ash toxicity index HICA + ε; Where β is the constant term (intercept), and ε is the random error; our goal is to find a set of values ​​for A, B, and C using mathematical optimization algorithms (such as least squares) that minimizes the overall error (such as the sum of squared residuals) between the predicted CPI values ​​calculated by the model and the actual CPI values ​​from all historical data; we perform a significance test (P-value) to check whether each coefficient (A, B, C) has a significant impact on CPI; if the P-value of a certain coefficient is greater than 0.05, it may mean that the indicator is not very important in this dataset, and we need to consider whether to remove it from the model or re-examine it; goodness of fit (R²): to determine the extent to which the model can explain the changes in CPI as a whole; the closer R² is to 1, the better the model fits, and the more reliable the found A / B / C values ​​are.

[0028] Select the A, B, and C values ​​obtained from the regression to obtain the comprehensive performance index; CPI = A × Dynamic burnout rate DBR N +B×Residual Carbon Reactivity Index (RCRI) N - C× Hazard Index of Coal Ash (HICA) N ; Since the dimensions of each indicator are different, normalization processing (0-1 standardization) is required. (DBR) N RCRI N HICA N All data are normalized. Dynamic burnout rate (baseline range: 60%-90%), DBR N = (DBR-60) / (90-60); Residual carbon reactivity index (benchmark range: 0.5-2.0 % / min), RCRI N =(RCRI-0.5) / (2.0-0.5); Hazard index of coal ash (benchmark range: 0-10), HICA=1-(HICA-0) / (10-0)=0.543.

[0029] A comprehensive performance evaluation system for pulverized coal injection in blast furnaces based on combustion and reaction kinetics includes: Residual carbon preparation unit: used to prepare standardized residual carbon samples; the residual carbon preparation unit includes a high-temperature tubular furnace, a preheating gas supply system, a feeding device, a sampling system, and a tail gas analysis system. The high-temperature tubular furnace is used to simulate the extreme conditions of the blast furnace tuyeres for experiments. The preheating gas supply system is used to introduce preheating gas at a preset temperature into the high-temperature tubular furnace. The feeding device is used to feed dried, ground, and sieved coal powder 12 into the high-temperature tubular furnace. The sampling system is used to collect incompletely burned residual carbon. The tail gas analysis system is used to detect the composition of the discharged gas. The high-temperature tubular furnace is equipped with a heating element 3, a corundum tube 5 and a thermocouple 10. The thermocouple 10 is inserted into the corundum tube 5 from the top, and the heating element 3 is disposed on the outer wall of the corundum tube 5. The preheating gas supply system includes an oxygen inlet pipe 1 and a gas preheating and flow controller a2. The oxygen inlet pipe 1 is connected to the lower part of the corundum tube 5, and the gas preheating and flow controller a2 is installed on the oxygen inlet pipe 1. The feeding device includes a storage tank 7, a feeding lever 8, a gas preheating and flow controller b9, a pulverized coal injection pipe 11, and a nitrogen inlet pipe 13. The nitrogen inlet pipe 13 is connected to the storage tank 7. A gas preheating and flow controller b9 is installed on the pipe between the storage tank 7 and the nitrogen inlet pipe 13. The feeding lever 8 is located at the outlet of the storage tank 7. The pulverized coal injection pipe 11 is inserted into the corundum pipe 5 from the top and connected to the outlet of the storage tank 7. The sampling system includes a water-cooled collector 14 and a sampler 15. The water-cooled collector 14 is located at the bottom of the corundum tube 5, and the sampler 15 is inserted into the water-cooled collector 14 and located directly below the bottom of the corundum tube 5. The exhaust gas analysis system includes a gas analyzer 4 and an exhaust pipe 6. The exhaust pipe 6 is inserted into the corundum tube 5, and the exhaust port of the part of the corundum tube 5 that is exposed is connected to the gas analyzer 4. The high-temperature tubular furnace mainly provides reaction space and heat. At the start of the experiment, the pulverized coal 12 in the storage tank 7 is output through the control of the feed lever 8, and preheated nitrogen is used as the transport gas and is injected into the reaction area of ​​the corundum tube 5 through the nitrogen inlet pipe 13. The preheated nitrogen is controlled by the gas preheating and flow controller b9 to control its preheating temperature and flow rate. Preheated oxygen is introduced into the lower part through the oxygen inlet pipe 1 as the reactive gas. The preheated oxygen is controlled by the gas preheating and flow controller a2 to control its preheating temperature and flow rate. The temperature inside the corundum tube 5 is kept constant by the heating element 3 and the thermocouple 10. After the reaction is completed, the solid residue falls due to gravity. The water-cooled collector 14 and the sampler 15 are used to cool, collect and sample the residue. The gas components are discharged from the upper gas outlet pipe 6 and the gas components are detected by the gas analyzer 4. Reactivity testing unit: used to test the reactivity of standard residual carbon samples; the reactivity unit includes a thermogravimetric analyzer, a high-purity CO2 gas source and a temperature control system. The thermogravimetric analyzer is used to measure the relationship between temperature and mass change of the standard residual carbon sample. The high-purity CO2 gas source is used to introduce CO2 into the thermogravimetric analyzer. The temperature control system is used to adjust the temperature of the isothermal reaction zone inside the thermogravimetric analyzer. Data acquisition and processing unit: used to collect data from coal ash, reactivity testing unit, and residual carbon, and to calculate the dynamic burnout rate, residual carbon reactivity, and coal ash behavior index of pulverized coal injected into the blast furnace. The data acquisition and processing unit includes a balance, a gas mass spectrometer, and a computer. The balance is connected to the reactivity testing unit to collect data from the reactivity testing unit. The gas mass spectrometer is used to analyze the composition and content of the gas after the reaction. The computer is used to automatically record data and establish models for dynamic burnout rate, residual carbon reactivity, and coal ash behavior index, and to calculate the comprehensive performance index (CPI) for evaluating pulverized coal injected into the blast furnace.

[0030] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0031] Example 1 1. Sample Information: High-quality thermal coal; Industrial analysis: Volatile matter: 25.8%; Fixed carbon: 62.3%; Ash: 9.5%; Moisture: 2.4%; Elemental analysis: C: 78.5%; H: 4.3%; O: 14.8%; N: 1.4%; S: 1.0%.

[0032] 2. Test results of key performance indicators; 2.1 Dynamic burnout rate determination Test conditions: High-temperature tube furnace temperature 1450℃; residence time 180ms; preheated air temperature 950℃; Test results: Initial coal powder carbon content: 8.200g × 78.5% = 6.437g; residual carbon content: 1.650g × 84.2% = 1.389g; Dynamic burnout rate (DBR) = (1 - 1.389 / 6.437) × 100% = 78.4%; 2.2 Determination of residual carbon reactivity; Test conditions: thermogravimetric analyzer, CO2 atmosphere; heating rate: 15℃ / min, final temperature 1350℃; Test results: (Time to achieve 50% conversion rate) = 42.5 min; Residual carbon reactivity index RCR = 0.5 / 42.5 × 100% = 1.18 % / min; 2.3 Calculation of the Hazard Index of Coal Ash Coal ash composition analysis: K2O: 1.8%, Na2O: 0.9%, Fe2O3: 7.2%; Ash softening temperature ST: 1280℃; HICA=[0.6×(K2O+Na2O)+0.4×Fe2O3]×(1300 / ST) =[0.6×(1.8+0.9)+0.4×7.2]×(1300 / 1280) =[1.62+2.88]×1.016=4.57 3. Calculation of the Comprehensive Performance Index (CPI); 3.1 Data Normalization Processing Dynamic burnout rate normalized value (DBR) N =(78.4-60) / (90-60)=0.613 Residual carbon reactivity index normalized value (RCRI) N =(1.18-0.5) / (2.0-0.5)=0.453 Normalized Index of Hazardousness of Coal Ash (HICA) N =1-(4.57-0) / (10-0)=0.543 3.2 Determination of Weighting Coefficients Based on regression analysis of the actual coal-coke replacement ratio from two years of production data of a large steel plant, the following results were obtained: A (Dynamic burnout rate weight) = 0.52; B (Residual carbon reactivity weight) = 0.35; C (Coal ash toxicity weight) = 0.13 3.3 CPI Calculation CPI = A × DBRN +B×RCRI N -C×HICA N =0.52×0.613+0.35×0.453-0.13×0.543 =0.319+0.159-0.071 =0.407 Converted to a percentage system: CPI = 0.407 × 100 = 40.7.

[0033] Example 2 1. Sample Information: High volatile bituminous coal; Industrial analysis: Volatile matter: 31.2%; Fixed carbon: 57.8%; Ash: 8.5%; Moisture: 2.5%; Elemental analysis: C: 74.6%; H: 5.1%; O: 17.8%; N: 1.5%; S: 1.0%.

[0034] 2. Test results of key performance indicators; 2.1 Dynamic burnout rate determination Test conditions: High-temperature tube furnace temperature 1420℃; residence time 150ms; preheated air temperature 920℃; Test results: Initial coal powder carbon content: 7.800g × 74.6% = 5.819g; residual carbon content: 1.120g × 81.5% = 0.913g; Dynamic burnout rate (DBR) = (1 - 0.913 / 5.819) × 100% = 84.3%; 2.2 Determination of residual carbon reactivity; Test conditions: thermogravimetric analyzer, CO2 atmosphere; heating rate: 15℃ / min, final temperature 1320℃; Test results: (Time to achieve 50% conversion rate) = 35.2 min; Residual carbon reactivity index RCR = 0.5 / 35.2 × 100% = 1.42% / min; 2.3 Calculation of the Hazard Index of Coal Ash Coal ash composition analysis: K2O: 2.1%, Na2O: 1.2%, Fe2O3: 8.5%; Ash softening temperature ST: 1240℃; HICA=[0.6×(K2O+Na2O)+0.4×Fe2O3]×(1300 / ST) =[0.6×(2.1+1.2)+0.4×8.5]×(1300 / 1240) =[1.98+3.40]×1.048=5.64 3. Calculation of the Comprehensive Performance Index (CPI); 3.1 Data Normalization Processing Dynamic burnout rate normalized value (DBR) N =(84.3-60) / (90-60)=0.810 Residual carbon reactivity index normalized value (RCRI) N =(1.42-0.5) / (2.0-0.5)=0.613 Normalized Index of Hazardousness of Coal Ash (HICA) N =1-(45.64-0) / (10-0)=0.436 3.2 Determination of Weighting Coefficients Based on regression analysis of the actual coal-coke replacement ratio from two years of production data of a large steel plant, the following results were obtained: A (Dynamic burnout rate weight) = 0.52; B (Residual carbon reactivity weight) = 0.35; C (Coal ash toxicity weight) = 0.13 3.3 CPI Calculation CPI = A × DBR N +B×RCRI N -C×HICA N =0.52×0.810+0.35×0.613-0.13×0.436 =0.421+0.215-0.057 =0.579 Converted to a percentage system: CPI = 0.579 × 100 = 57.9.

[0035] Example 3 1. Sample Information: Low volatile anthracite Industrial analysis: Volatile matter: 6.5%; Fixed carbon: 82.1%; Ash: 9.8%; Moisture: 1.6%; Elemental analysis: C: 87.2%; H: 2.1%; O: 8.3%; N: 1.2%; S: 1.2%.

[0036] 2. Test results of key performance indicators; 2.1 Dynamic burnout rate determination Test conditions: High-temperature tube furnace temperature 1480℃; residence time 250ms; preheated air temperature 940℃; Test results: Initial pulverized coal carbon content: 9.500g × 87.2% = 8.284g; Residual carbon content: 4.850g × 89.1% = 4.321g; Dynamic burnout rate (DBR) = (1 - 4.321 / 8.284) × 100% = 47.8%; 2.2 Determination of residual carbon reactivity; Test conditions: thermogravimetric analyzer, CO2 atmosphere; heating rate: 15℃ / min, final temperature 1350℃; Test results: (Time to achieve 50% conversion rate) = 58.6 min; Residual carbon reactivity index RCR = 0.5 / 58.6 × 100% = 0.85% / min; 2.3 Calculation of the Hazard Index of Coal Ash Coal ash composition analysis: K2O: 0.8%, Na2O: 0.5%, Fe2O3: 5.2%; Ash softening temperature ST: 1380℃; HICA=[0.6×(K2O+Na2O)+0.4×Fe2O3]×(1300 / ST) =[0.6×(0.8+0.5)+0.4×5.2]×(1300 / 1380) =[0.78+2.08]×0.942=2.69 3. Calculation of the Comprehensive Performance Index (CPI); 3.1 Data Normalization Processing Dynamic burnout rate normalized value (DBR) N =(47.8-60) / (90-60)=-0.407 Residual carbon reactivity index normalized value (RCRI) N =(0.85-0.5) / (2.0-0.5)=0.233 Normalized Index of Hazardousness of Coal Ash (HICA) N =1-(2.69-0) / (10-0)=0.731 3.2 Determination of Weighting Coefficients Based on regression analysis of the actual coal-coke replacement ratio from two years of production data of a large steel plant, the following results were obtained: A (Dynamic burnout rate weight) = 0.52; B (Residual carbon reactivity weight) = 0.35; C (Coal ash toxicity weight) = 0.13 3.3 CPI Calculation CPI = A × DBR N +B×RCRI N -C×HICA N =0.52×(-0.407)+0.35×0.233-0.13×0.731 =-0.212+0.082-0.095 =-0.225 Converted to a percentage system: CPI = -0.225 × 100 = -22.5.

Claims

1. A method for evaluating the comprehensive performance of pulverized coal injected into blast furnaces based on combustion and reaction kinetics, characterized in that, Includes the following steps: S1. Prepare standard residual carbon samples, conduct combustion experiments and collect data; S2. Calculate the dynamic burnout rate of pulverized coal injected into the blast furnace; S3. Calculate the reactivity of residual carbon in pulverized coal injected into the blast furnace. S4. Calculate the coal ash behavior index, which is used to evaluate the degree of harm of coal ash to blast furnace smelting. S5. Establish a model for dynamic burnout rate, residual carbon reactivity, and ash behavior index, and calculate the comprehensive performance index (CPI) for evaluating pulverized coal injection in blast furnaces: CPI = A × Dynamic burnout rate + B × Residual carbon reactivity index - C × Coal ash behavior index; Wherein, CPI is the comprehensive performance index of pulverized coal injected into blast furnace; A is the dynamic burnout rate weighting coefficient, with a value range of 0.4 to 0.6; B is the weighting coefficient of residual carbon reactivity index, with a value range of 0.3 to 0.5; C is the weighting coefficient of coal ash toxicity index, with a value range of 0.1 to 0.63; and A+B+C=1, the weighting coefficients A, B, and C are obtained through industrial data regression analysis.

2. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 1, characterized in that, Step 1 specifically includes the following steps: S1.1 The coal powder sample to be tested is dried, ground and sieved, and then sent into a high-temperature tube furnace; S1.2 Set the experimental parameters of the high-temperature tubular furnace to simulate the extreme conditions in the blast furnace tuyeres. Simultaneously start the infrared gas analyzer to perform online gas analysis and record the flue gas concentrations of O2, CO, and CO2 in real time. S1.3 Collect unburned carbon residue.

3. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 2, characterized in that, The experimental parameters are as follows: preheated air is introduced into the high-temperature tubular furnace; the temperature of the constant temperature zone inside the furnace is controlled at 1300-1500℃; the residence time of pulverized coal in the constant temperature zone inside the furnace is controlled within 50-500ms; the preheated air temperature is selected as 850-950℃; the pulverized coal feeding rate is 0.2-0.8g / min; and the carrier gas flow rate N2 is 0.5-1.0L / min.

4. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 1, characterized in that, Step S2 employs a dual-method parallel calculation of the burnout rate; Gas analysis method for calculating burnout rate DBR1: DBR1 = (M Cgas / M Cin )×100%; Carbon balance method for calculating burnout rate DBR2: DBR2 = [1 - (M residual ×C residual ) / (M coal ×C coal )]×100%; Among them, M Cgas M is the mass flow rate of carbon, in kg / h. Cin M is the carbon feed rate, in kg / h. residual The mass of collected residual carbon is expressed in kg; C residual M represents the carbon mass content in the collected residual carbon. coal Initial coal powder mass, unit: kg; C coal This represents the initial carbon mass content in the pulverized coal. Result verification and output; Calculate the absolute difference ΔDBR = |DBR1 - DBR2|; When ΔDBR≤3%, the test is considered valid, and the final dynamic burnout rate DBR=(DBR1+DBR2) / 2; If ΔDBR > 3%, the test is deemed invalid and the system's sealing, sample representativeness, or measuring instruments must be checked before the test is repeated.

5. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 4, characterized in that, The gas analysis method is used to calculate the burnout rate, where the pulverized coal feed rate is set to M. coal The unit is kg / h; the mass fraction of carbon in pulverized coal is C. coal Then the carbon feed rate is: M Cin =M coal ×C coal ; In the outlet gas, the volume fractions of CO and CO2 were measured to be [CO] and [CO2], respectively, and the total gas flow rate was measured to be V. gas Unit m 3 / h; The molar flow rates of CO and CO2 are: n CO =(V gas ×[CO]×1000) / 22.4; n CO2 =(Vgas×[CO2]×1000) / 22.4; The molar flow rate of carbon in the outlet gas is: n Cgas =n CO +n CO2 ; Where, n CO n is the molar flow rate of CO, in mol / h; CO2 n is the molar flow rate of CO2, in mol / h. Cgas The molar flow rate of carbon in the outlet gas, in mol / h; The mass flow rate of carbon is: M Cgas =n Cgas ×m c / 1000; Where, m c m is the molar mass of carbon. c =12g / mol.

6. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 1, characterized in that, Step S3 specifically includes the following steps: (1) Gasification reaction test: The prepared standard carbon residue sample is placed in a thermogravimetric analyzer and heated from room temperature to 1100-1500℃ at a heating rate of 10-20℃ / min under a 100% CO2 atmosphere, or the standard carbon residue sample is reacted with CO2 under a constant temperature condition of 1100-1300℃. (2) Reactivity Calculation: The mass change curve of the sample during the reaction process is recorded in real time. Based on this curve, the gasification reactivity index (RCRI) of residual carbon is calculated using the following formula: RCRI=(0.5 / )×100%; in, The RCRI value represents the time required for the residual carbon sample to reach a conversion rate of 50%. The higher the RCRI value, the higher the gasification reactivity of the residual carbon.

7. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 1, characterized in that, The calculation is used to evaluate the degree of harm of coal ash to blast furnace smelting. HICA = [w1× (K2O + Na2O) + w2 × Fe2O3] × f(ST); Wherein, HICA is the toxicity index of coal ash, K2O is the mass percentage of K2O component in coal ash, Na2O is the mass percentage of Na2O component in coal ash, Fe2O3 is the mass percentage of Fe2O3 component in coal ash, and w1, w 2分别 The weighting coefficients of (K2O + Na2O) and Fe2O3 are given, and w1 + w2 = 1, and w1 > w2. ST is the softening temperature of coal ash, and f(ST) is the temperature correction function. f(ST) = A / ST; Where A is a constant of the temperature correction function, with a value ranging from 1000 to 1500.

8. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 7, characterized in that, The weighting coefficient w1 ranges from 0.5 to 0.8, and the weighting coefficient w2 ranges from 0.2 to 0.

5.

9. The method for evaluating the comprehensive performance of pulverized coal injection in blast furnaces based on combustion and reaction kinetics as described in claim 8, characterized in that, The weighting coefficient w1 ranges from 0.6 to 0.7, and the weighting coefficient w2 ranges from 0.3 to 0.

4.

10. A system for implementing the comprehensive performance evaluation method of pulverized coal injection in blast furnace based on combustion and reaction kinetics as described in any one of claims 1 to 9, characterized in that, include: Residual carbon preparation unit: used to prepare standardized residual carbon samples; the residual carbon preparation unit includes a high-temperature tubular furnace, a preheating gas supply system, a feeding device, a sampling system, and a tail gas analysis system. The high-temperature tubular furnace is used to simulate the extreme conditions of the blast furnace tuyeres for experiments. The preheating gas supply system is used to introduce preheating gas at a preset temperature into the high-temperature tubular furnace. The feeding device is used to feed dried, ground, and sieved coal powder into the high-temperature tubular furnace. The sampling system is used to collect incompletely burned residual carbon. The tail gas analysis system is used to detect the composition of the emitted gas. Reactivity testing unit: used to test the reactivity of standard residual carbon samples; the reactivity unit includes a thermogravimetric analyzer, a high-purity CO2 gas source and a temperature control system. The thermogravimetric analyzer is used to measure the relationship between temperature and mass change of the standard residual carbon sample. The high-purity CO2 gas source is used to introduce CO2 into the thermogravimetric analyzer. The temperature control system is used to adjust the temperature of the isothermal reaction zone inside the thermogravimetric analyzer. Data acquisition and processing unit: used to collect data from coal ash, reactivity testing unit, and residual carbon, and to calculate the dynamic burnout rate, residual carbon reactivity, and coal ash behavior index of pulverized coal injected into the blast furnace. The data acquisition and processing unit includes a balance, a gas mass spectrometer, and a computer. The balance is connected to the reactivity testing unit to collect data from the reactivity testing unit. The gas mass spectrometer is used to analyze the composition and content of the gas after the reaction. The computer is used to automatically record data and establish models for dynamic burnout rate, residual carbon reactivity, and coal ash behavior index, and to calculate the comprehensive performance index (CPI) for evaluating pulverized coal injected into the blast furnace.

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