Method for simulating hydrogen-rich blast furnace tuyere coal combustion rate

Abstract

This invention provides a method for simulating and testing the combustion rate of pulverized coal at the tuyere of a hydrogen-rich blast furnace. The method involves determining the amount of hydrogen-rich gas injected into a single tuyere, the amount of pulverized coal injected, the amount of oxygen injected, and the amount of carrier gas injected based on the process parameters of the hydrogen-rich blast furnace. The molar amounts of carbon and oxygen atoms, the oxygen-to-carbon ratio, and the volume ratio of oxygen to hydrogen-rich gas are then calculated. By combining the pipeline of a novel blast furnace composite injection simulation experimental device, the experimental oxygen volume and hot blast volume are obtained, thereby calculating the amount of pulverized coal injected, the amount of hydrogen-rich gas, the volume fraction of oxygen in the carrier gas, and the nitrogen integral number under the experimental conditions. Finally, experiments are conducted based on the obtained experimental parameters, and the combustion rate is calculated using the experimental results. This invention scientifically calculates the actual operating conditions of a hydrogen-rich blast furnace, obtains the simulation parameters under experimental conditions, and conducts combustion rate experiments. It simulates the behavior of pulverized coal injection into the furnace and its combustion process, accurately reflecting the actual combustion rate of pulverized coal at the tuyere, and has guiding significance for the actual production of hydrogen-rich blast furnaces.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method for simulating and testing the combustion rate of pulverized coal at the tuyeres of a hydrogen-rich blast furnace. Background Technology

[0002] Pulverized coal injection in blast furnaces is currently one of the effective means to replace expensive metallurgical coke, reduce production costs, and improve production efficiency. High temperature, high pressure, and multi-component gas are typical characteristics of the three regions of the blast furnace: direct-blown pipe, tuyeres, and swirl zone. This is because the temperature of the hot blast blown into the blast furnace is approximately 1200℃, and the pressure is approximately 0.4MPa, resulting in a high-speed turbulent flow of hot blast at the direct-blown pipe. Therefore, once pulverized coal is injected into the direct-blown pipe, it is rapidly heated, with a heating rate as high as 10... 3 ~10 6 ℃·s -1 Furthermore, the residence time of pulverized coal in the direct-fired tube is very short, only about 10ms. Such a short residence time poses a challenge to whether the pulverized coal can be fully combusted. If the pulverized coal is not fully combusted, resulting in too much unburned pulverized coal remaining in the furnace, it may increase the viscosity of the slag, cause accumulation in the hearth, reduce the porosity of the burden, increase the resistance to the passage of gas in the furnace, and affect the stable operation of the blast furnace. Therefore, whether the injected pulverized coal can be fully combusted at the blast furnace tuyeres is crucial to the blast furnace ironmaking industry.

[0003] Invention patent (application number CN) Patent 202010136078.1 discloses a method for determining the test parameters of pulverized coal combustion rate in blast furnaces under different coal ratios. Based on the ratio of the horizontal cross-sectional area of ​​the blast furnace tuyeres to the cross-sectional area of ​​the crucible in the pulverized coal combustion rate test, the air flow rate in the pulverized coal combustion rate test is determined. Based on the ratio of the air flow rate to the blast furnace blast volume under a set coal ratio M, the weight of pulverized coal in the pulverized coal combustion test is determined, thus completing the determination of the test parameters of pulverized coal combustion rate under coal ratio M. Although this method references actual parameters such as the horizontal cross-sectional area of ​​the blast furnace tuyeres and the blast furnace blast volume, its pulverized coal combustibility test method is thermogravimetric analysis, which measures the combustion performance of pulverized coal based on different heating rates or temperatures. This test method differs significantly from the actual behavior of pulverized coal in a blast furnace. In actual production, after pulverized coal is injected into the blast furnace, it is rapidly heated and in a high-speed motion state, resulting in a short residence time in the tuyeres tuyeres. Therefore, the test error of the pulverized coal combustion rate in the above patent is relatively large, and the results still cannot accurately reflect the combustion situation of pulverized coal in the blast furnace.

[0004] In recent years, with the continuous maturation of blast furnace pulverized coal injection technology, in order to reduce energy consumption, a technology has emerged that uses hydrogen-rich gas to replace part of the pulverized coal injected into the blast furnace through the tuyeres. Furthermore, a simulation test device for simultaneously injecting pulverized coal and hydrogen-rich gas into the blast furnace (utility model patent application number CN 202220205492.8) has been invented to simulate this type of working condition. However, how to convert the actual working conditions of the blast furnace tuyeres swirling zone to laboratory experimental conditions, so that the experimental results are closer to the actual field conditions and can guide actual production, is a problem that blast furnace ironmaking workers are eager to solve.

[0005] In view of this, it is necessary to design an improved method for simulating and testing the pulverized coal combustion rate at the tuyeres of hydrogen-rich blast furnaces in order to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a method for simulating and testing the combustion rate of pulverized coal at the tuyeres of a hydrogen-rich blast furnace. By using a novel blast furnace composite injection simulation experimental device, a series of scientific calculations are performed on the actual operating conditions of the hydrogen-rich blast furnace to obtain the simulation parameters under the experimental conditions, and a combustion rate experiment is conducted to more accurately simulate the combustion rate of pulverized coal at the blast furnace tuyeres. This has important guiding significance for the actual production of hydrogen-rich blast furnaces.

[0007] To achieve the above-mentioned objective, this invention provides a method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace, comprising the following steps:

[0008] S1. Determine the amount of hydrogen-rich gas injected through a single tuyer, the amount of coal injected through a single tuyer, the amount of oxygen-rich gas injected through a single tuyer, and the amount of carrier gas injected through a single tuyer based on the actual process parameters of the blast furnace.

[0009] S2. Determine the molar amount of carbon atoms in a single vent by the amount of coal injected into a single vent as described in step S1, and determine the molar amount of oxygen atoms in a single vent by the amount of oxygen-enriched gas injected into a single vent, thereby obtaining the oxygen-carbon ratio; obtain the volume ratio of oxygen and hydrogen-enriched gas by the amount of oxygen-enriched gas injected into a single vent and the amount of hydrogen-enriched gas injected into a single vent.

[0010] S3. Based on the pipeline of the new blast furnace composite injection simulation experimental device, the experimental oxygen volume and experimental hot air volume are obtained. Based on the oxygen-carbon atomic ratio and the volume ratio of oxygen and hydrogen-rich gas, the experimental pulverized coal injection amount, experimental hydrogen-rich gas injection amount, oxygen volume fraction and nitrogen gas integral number in the experimental carrier gas are calculated under the experimental conditions.

[0011] S4. Based on the experimental pulverized coal injection rate, experimental hydrogen-rich gas injection rate, oxygen volume fraction in the experimental carrier gas, and nitrogen gas integral number obtained in step S3, conduct experiments in the novel blast furnace composite injection simulation experimental device, and calculate the combustion rate based on the results of the gas analyzer; the formula for calculating the combustion rate is as follows:

[0012]

[0013] In the formula: X CO These are the mole fractions of CO2 and CO generated from the combustion of 0.1g of pulverized coal, as measured by the gas analyzer. This represents the theoretical mole fraction of CO2 produced by the complete combustion of carbon in pulverized coal and hydrogen-rich gas.

[0014] As a further improvement of the present invention, in step S4... The calculation method is as follows: In the formula, N is the molar amount of N mol coal powder and carbon in hydrogen-rich gas that is completely converted into CO2; Q includes the molar amount of coal powder and decomposed gas in hydrogen-rich gas as measured by the gas analyzer; L is L mol gas, including gas that has not been in contact with coal powder and has entered the gas collecting bottle beforehand, as well as gas that has collided and mixed with coal powder during injection.

[0015] Where N = n C +n CH4 n C n is the molar amount of carbon in pulverized coal. CH4 To determine the molar amount of CH4 in the hydrogen-rich gas being injected in the experiment, V 富氢气体 The amount of hydrogen-rich gas injected in the experiment, W CH4 The mass fraction of CH4 in the hydrogen-rich gas injected in the experiment.

[0016] As a further improvement of the present invention, in step S1, the actual process parameters of the blast furnace include the blast furnace hydrogen-rich gas injection rate, blast furnace coal ratio, blast furnace molten iron production rate, blast furnace blast volume, oxygen enrichment rate, and pulverized coal carrier gas volume.

[0017] As a further improvement of the present invention

[0018] The formula for calculating the amount of hydrogen-rich gas injected through a single air outlet is as follows: In the formula, D NG The amount of hydrogen-rich gas injected from a single air outlet, m 3 / s, V NG The amount of hydrogen-rich gas injected into the blast furnace per minute is m. 3 / min, where Z is the number of blast furnace tuyeres;

[0019] The formula for calculating the coal injection rate at a single air outlet is as follows: In the formula, D PC P is the pulverized coal injection rate per tuyer (kg / s), M is the blast furnace coal ratio (kg / t), and P is the pulverized coal injection rate per tuyer (kg / t). pig The blast furnace hot metal production rate is expressed in t / h.

[0020] The formula for calculating the oxygen enrichment capacity of a single air outlet is as follows: In the formula, D OxygenFor single-outlet oxygen enrichment, m 3 / s, V B-con For blast furnace blast volume, m 3 / min, Oxygen enrichment rate, %;

[0021] The formula for calculating the carrier air volume injected through a single air outlet is as follows: In the formula, For single-nozzle injection of carrier air, m 3 / s, For pulverized coal gas carrier gas volume, m 3 / min.

[0022] As a further improvement of the present invention, in step S2...

[0023] The formula for calculating the molar amount of carbon atoms in a single air outlet is: In the formula, n C-con Molar amount of carbon atoms per air outlet, mol / s, m C-coal The carbon content of pulverized coal is fixed, in %;

[0024] The formula for calculating the molar amount of oxygen atoms at a single air outlet is as follows: In the formula, n O-con The molar amount of oxygen atoms per air outlet, in mol / s;

[0025] The formula for calculating the oxygen-to-carbon atomic ratio is: In the formula, A O / C The ratio of oxygen to carbon atoms;

[0026] The formula for calculating the volume ratio of oxygen to hydrogen-rich gas is as follows: In the formula, This represents the volume ratio of oxygen to hydrogen-rich gas.

[0027] As a further improvement of the present invention, in step S3...

[0028] The formula for calculating the amount of pulverized coal injected in the experiment is as follows:

[0029] In the formula, M coal-exp For the experimental pulverized coal injection rate, kg; n C-exp The molar amount of carbon under experimental conditions, in mol / s. Where, n O-exp The molar amount of oxygen under experimental conditions, in mol / s. In the formula, The volume of oxygen in the experiment, m 3 V hw-fixed The volume of the experimental hot air is m. 3 ;

[0030] The formula for calculating the amount of hydrogen-rich gas injected in the experiment is as follows: In the formula, V NG-exp To test the amount of hydrogen-rich gas injected, m 3 ;

[0031] The formula for calculating the volume fraction of oxygen in the experimental carrier gas is as follows: In the formula, The oxygen volume fraction, in % (including carrier gas);

[0032] The formula for calculating the nitrogen gas integral is as follows: In the formula, This is the nitrogen gas integral including the carrier gas volume, expressed as a percentage.

[0033] As a further improvement of the present invention, the gases decomposed in the coal powder and hydrogen-rich gas include hydrogen, oxygen and nitrogen decomposed from the coal powder, and CO and hydrogen decomposed from the hydrogen-rich gas.

[0034] As a further improvement of the present invention, in step S3 or step S4, the novel blast furnace composite injection simulation experimental device includes a combustion furnace, a pulverized coal injection system and a hydrogen-rich gas injection system connected to the combustion furnace.

[0035] As a further improvement of the present invention, in step S3, a mixed gas is customized as an experimental carrier gas according to the obtained oxygen volume fraction and nitrogen gas integral number. The experimental carrier gas and pulverized coal that meet the experimental pulverized coal injection amount are injected into the combustion furnace from the pulverized coal injection system. Hydrogen-rich gas is injected into the hydrogen-rich gas injection system according to the experimental pulverized hydrogen gas injection amount to simulate the actual dynamics of pulverized coal at the blast furnace tuyeres.

[0036] As a further improvement of the present invention, the novel blast furnace composite injection simulation experimental device also includes a pressure control system, a flow control system and a vacuum pump, used to control the pressure and flow rate of the gas entering the combustion furnace.

[0037] The beneficial effects of this invention are:

[0038] 1. The method for simulating and testing the pulverized coal combustion rate at the tuyere of a hydrogen-rich blast furnace according to the present invention determines the amount of hydrogen-rich gas injected at a single tuyere, the amount of pulverized coal injected, the amount of oxygen injected, and the amount of carrier gas injected based on the actual process parameters of the blast furnace. Then, the molar amount of carbon atoms, the molar amount of oxygen atoms, the oxygen-carbon ratio, and the volume ratio of oxygen to hydrogen-rich gas at a single tuyere are calculated. Next, the experimental oxygen volume and experimental hot blast volume are obtained by combining the pipeline of a novel blast furnace composite injection simulation experimental device, thereby calculating the amount of pulverized coal injected, the amount of hydrogen-rich gas, the volume fraction of oxygen in the carrier gas, and the integral number of nitrogen gas under the experimental conditions. Finally, an experiment is conducted in the experimental device based on the obtained experimental parameters, and the combustion rate is calculated based on the results of the gas analyzer. This invention utilizes a novel blast furnace composite injection simulation experimental device to perform a series of scientific calculations on the actual operating conditions of a hydrogen-rich blast furnace, obtain the simulated experimental parameters under the experimental conditions, and conduct combustion rate experiments. This more accurately simulates the state of pulverized coal at the blast furnace tuyere, resulting in a more accurate combustion rate, which has important guiding significance for the actual production of hydrogen-rich blast furnaces.

[0039] 2. The method for simulating and testing the pulverized coal combustion rate at the tuyere of a hydrogen-rich blast furnace of the present invention establishes the relationship between pulverized coal injection and the carbon-oxygen atomic ratio through mathematical derivation, and calculates the amount of pulverized coal injected in the experiment; relying on a novel blast furnace composite injection simulation experimental device, the injection volume of hydrogen-rich gas and the volume fraction of oxygen and nitrogen in the carrier gas are calculated through relevant blast furnace injection parameters; by simulating the behavior of pulverized coal injection into the furnace and its combustion process in an actual blast furnace in the experimental device, the actual combustion rate of pulverized coal at the tuyere of a hydrogen-rich blast furnace is reflected more accurately. Attached Figure Description

[0040] Figure 1 This is a schematic flowchart of the method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace according to the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0043] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0044] Please see Figure 1 As shown, a method for simulating and testing the pulverized coal combustion rate at the tuyere of a hydrogen-rich blast furnace includes the following steps:

[0045] S1. Determine the amount of hydrogen-rich gas injected through a single tuyer, the amount of pulverized coal injected through a single tuyer, the amount of oxygen-enriched gas injected through a single tuyer, and the amount of carrier gas injected through a single tuyer based on the actual process parameters of the blast furnace. The actual process parameters of the blast furnace include the amount of hydrogen-rich gas injected through the blast furnace, the blast furnace coal ratio, the blast furnace hot metal production rate, the blast furnace blast volume, the oxygen enrichment rate, and the amount of pulverized coal and carrier gas injected.

[0046] The formula for calculating the amount of hydrogen-rich gas injected from a single air outlet is: In the formula, D NG The amount of hydrogen-rich gas injected from a single air outlet, m 3 / s, V NG The amount of hydrogen-rich gas injected into the blast furnace per minute is m. 3 / min, where Z is the number of blast furnace tuyeres;

[0047] The formula for calculating the amount of coal injected at a single air inlet is: In the formula, D PC P is the pulverized coal injection rate per tuyer (kg / s), M is the blast furnace coal ratio (kg / t), and P is the pulverized coal injection rate per tuyer (kg / t). pig The blast furnace hot metal production rate is expressed in t / h.

[0048] The formula for calculating the oxygen enrichment capacity of a single air outlet is: In the formula, D Oxygen For single-outlet oxygen enrichment, m 3 / s, V B-con For blast furnace blast volume, m 3 / min, Oxygen enrichment rate, %;

[0049] The formula for calculating the carrier air volume of a single air outlet is: In the formula, For single-nozzle injection of carrier air, m 3 / s, For pulverized coal gas carrier gas volume, m 3 / min;

[0050] S2. Determine the molar amount of carbon atoms at a single tuyere from the coal injection rate at a single tuyere in step S1, and determine the molar amount of oxygen atoms at a single tuyere from the oxygen enrichment rate at a single tuyere, thus obtaining the oxygen-carbon ratio; obtain the volume ratio of oxygen to hydrogen-rich gas from the oxygen enrichment rate and the hydrogen-rich gas rate at a single tuyere; the specific calculations are as follows:

[0051] The formula for calculating the molar amount of carbon atoms in a single air vent is: In the formula, n C-con Molar amount of carbon atoms per air outlet, mol / s, m C-coal The carbon content of pulverized coal is fixed, in %;

[0052] The formula for calculating the molar amount of oxygen atoms at a single air outlet is: In the formula, n O-con The molar amount of oxygen atoms per air outlet, in mol / s;

[0053] The formula for calculating the oxygen-to-carbon atomic ratio is: In the formula, A O / C The ratio of oxygen to carbon atoms;

[0054] The formula for calculating the volume ratio of oxygen to hydrogen-rich gas is: In the formula, This represents the volume ratio of oxygen to hydrogen-rich gas.

[0055] S3. Based on the pipeline of the new blast furnace composite injection simulation experimental device, the experimental oxygen volume and experimental hot air volume are obtained. Based on the oxygen-carbon atomic ratio and the volume ratio of oxygen and hydrogen-rich gas, the experimental pulverized coal injection amount, experimental hydrogen-rich gas injection amount, oxygen volume fraction and nitrogen gas integral number in the experimental carrier gas are calculated under the experimental conditions.

[0056] Formula for calculating the amount of pulverized coal injected in the experiment:

[0057] In the formula, M coal-exp For the experimental pulverized coal injection rate, kg; n C-exp The molar amount of carbon under experimental conditions, in mol / s. Where, n O-exp The molar amount of oxygen under experimental conditions, in mol / s. In the formula, The volume of oxygen in the experiment, m 3 V hw-fixed The volume of the experimental hot air is m. 3 ;

[0058] Formula for calculating the amount of hydrogen-rich gas injected in the experiment: In the formula, V NG-exp To test the amount of hydrogen-rich gas injected, m 3 ;

[0059] Formula for calculating the volume fraction of oxygen in the experimental carrier gas: In the formula, The oxygen volume fraction, in % (including carrier gas);

[0060] Formula for calculating the nitrogen gas integral: In the formula, The percentage of nitrogen gas including carrier gas;

[0061] S4. Based on the experimental pulverized coal injection rate, experimental hydrogen-rich gas injection rate, oxygen volume fraction in the experimental carrier gas, and nitrogen gas integral number obtained in step S3, conduct experiments in a novel blast furnace composite injection simulation experimental device, and calculate the combustion rate based on the results of the gas analyzer; the formula for calculating the combustion rate is as follows:

[0062]

[0063] In the formula: X CO The values ​​are the mole fractions of CO2 and CO generated from the combustion of 0.1g of pulverized coal, as measured by a gas analyzer. Theoretically, this represents the mole fraction of CO2 generated from the complete combustion of carbon in pulverized coal and hydrogen-rich gas.

[0064] in, The calculation method is as follows: In the formula, N is the molar amount of N mol coal powder and carbon in hydrogen-rich gas that is completely converted into CO2; Q includes the molar amount of gas decomposed from coal powder and hydrogen-rich gas as measured by the gas analyzer; L is L mol of gas, including gas that enters the gas collecting bottle before contacting coal powder and gas that collides and mixes with coal powder during injection; it should be noted that the gas decomposed from coal powder and hydrogen-rich gas includes hydrogen, oxygen and nitrogen decomposed from coal powder, and CO and hydrogen decomposed from hydrogen-rich gas.

[0065] Where N = n C +n CH4 n C n is the molar amount of carbon in pulverized coal. CH4 To determine the molar amount of CH4 in the hydrogen-rich gas being injected in the experiment, V 富氢气体 To test the amount of hydrogen-rich gas injected, W CH4 The mass fraction of CH4 in the hydrogen-rich gas injected in the experiment.

[0066] A method for simulating the combustion rate of pulverized coal at the tuyere of a hydrogen-rich blast furnace was developed. The relationship between pulverized coal injection and the carbon-oxygen atomic ratio was established through mathematical derivation, and the amount of pulverized coal injected in the experiment was calculated. Relying on a novel blast furnace composite injection simulation experimental device, the injection volume of hydrogen-rich gas and the volume fraction of oxygen and nitrogen in the carrier gas were calculated under experimental conditions through relevant blast furnace injection parameters. By simulating the behavior of pulverized coal injection into the furnace and its combustion process in an actual blast furnace in the experimental device, the actual combustion rate of pulverized coal at the tuyere of a hydrogen-rich blast furnace was reflected relatively accurately.

[0067] Specifically, a mixed gas was customized as the experimental carrier gas based on the obtained oxygen volume fraction and nitrogen gas integral. The experimental carrier gas and pulverized coal that met the experimental injection amount were injected into the combustion furnace from the pulverized coal injection system. Hydrogen-rich gas was injected into the hydrogen-rich gas injection system according to the experimental injection amount to simulate the dynamics of pulverized coal at the tuyeres of an actual hydrogen-rich blast furnace.

[0068] In some specific embodiments, in step S3 or step S4, the novel blast furnace composite injection simulation experimental device includes a combustion furnace, a pulverized coal injection system and a hydrogen-rich gas injection system connected to the combustion furnace; it also includes a pressure control system, a flow control system and a vacuum pump, used to control the pressure and flow rate of the gas entering the combustion furnace; the novel blast furnace composite injection simulation experimental device uses a vacuum pump to discharge impurity gases in the device before the experiment, avoiding interference from impurity gases on the experimental and calculation results.

[0069] More specifically, the novel blast furnace composite injection simulation experimental device can adopt the device provided in the patent document with application number CN202220205492.8 and title "Simulation Experimental Device for Simultaneous Injection of Pulverized Coal and Hydrogen-Rich Gas into a Blast Furnace". The hydrogen-rich gas is input from the high-pressure gas inlet of the device, and oxygen and nitrogen are mixed according to the calculated volume fraction and directly used as carrier gas from the high-pressure gas inlet. After mixing with pulverized coal, pulverized coal is injected into the combustion furnace to realize the simulation of simultaneous injection of hydrogen-rich gas and pulverized coal into a blast furnace.

[0070] This invention utilizes a novel blast furnace composite injection simulation experimental device to perform a series of scientific calculations on the actual operating conditions of a hydrogen-rich blast furnace, obtain simulation experimental parameters under experimental conditions, and conduct combustion rate experiments. This more accurately simulates the state of pulverized coal at the blast furnace tuyeres, resulting in a more accurate combustion rate, which has important guiding significance for actual blast furnace production.

[0071] Example 1

[0072] This embodiment provides a method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace, including the following steps:

[0073] S1. Determine the amount of hydrogen-rich gas injected through a single tuyer, the amount of pulverized coal injected through a single tuyer, the amount of oxygen-enriched gas injected through a single tuyer, and the amount of carrier gas injected through a single tuyer based on the actual process parameters of the blast furnace. The actual process parameters of the blast furnace include the amount of hydrogen-rich gas injected through the blast furnace, the blast furnace coal ratio, the blast furnace hot metal production rate, the blast furnace blast volume, the oxygen enrichment rate, and the amount of pulverized coal and carrier gas injected.

[0074] The combined pulverized coal injection and hydrogen-rich gas of a certain blast furnace were selected for analysis. The basic production data of the blast furnace are shown in the table below:

[0075] Table 1 Basic Production Data of Blast Furnace

[0076]

[0077] Using the data in Table 1, the amount of hydrogen-rich gas injected into a single tuyer can be calculated from the amount of hydrogen-rich gas injected into the blast furnace. The calculation formula is as follows: In the formula, D NG The amount of hydrogen-rich gas injected from a single air outlet, m 3 / s, V NG The amount of hydrogen-rich gas injected into the blast furnace per minute is m. 3 / min, Z is the number of blast furnace tuyeres; D NG =0.151m 3 / s;

[0078] The pulverized coal injection rate per tuyer is calculated from the blast furnace coal ratio and blast furnace hot metal production rate. The calculation formula is as follows: In the formula, D PC P is the pulverized coal injection rate per tuyer (kg / s), M is the blast furnace coal ratio (kg / t), and P is the pulverized coal injection rate per tuyer (kg / t). pig D represents the blast furnace hot metal production rate, in t / h. PC =0.544 kg / s;

[0079] The oxygen enrichment amount injected at a single tuyere can be calculated from the blast furnace blast volume and oxygen enrichment rate using the following formula: In the formula, D Oxygen For single-outlet oxygen enrichment, m 3 / s, V B-con For blast furnace blast volume, m 3 / min, Oxygen enrichment rate, %; D Oxygen =1.034m 3 / s;

[0080] The single-inlet injection carrier gas volume is calculated from the pulverized coal injection carrier gas volume using the following formula: In the formula, For single-nozzle injection of carrier air, m 3 / s, For pulverized coal gas carrier gas volume, m 3 / min;

[0081] S2. Determine the molar amount of carbon atoms in a single tuyere by the amount of coal injected into a single tuyere in step S1, and determine the molar amount of oxygen atoms in a single tuyere by the amount of oxygen injected into a single tuyere, thereby obtaining the oxygen-carbon ratio.

[0082] The formula for calculating the molar amount of carbon atoms in a single air vent is: In the formula, n C-con Molar amount of carbon atoms per air outlet, mol / s, m C-coal The fixed carbon content of pulverized coal, %; n C-con = 36.265 mol / s;

[0083] The formula for calculating the molar amount of oxygen atoms at a single air outlet is: In the formula, n O-con The molar amount of oxygen atoms per air outlet, in mol / s;

[0084] The formula for calculating the oxygen-to-carbon atomic ratio is: In the formula, A O / C The ratio of oxygen to carbon atoms; A O / C =2.5455;

[0085] The volume ratio of oxygen to hydrogen-rich gas is obtained from the amount of oxygen-enriched gas injected from a single air outlet and the amount of hydrogen-enriched gas injected from a single air outlet; the specific calculation is as follows: The formula for calculating the volume ratio of oxygen to hydrogen-enriched gas is: In the formula, This represents the volume ratio of oxygen to hydrogen-rich gas.

[0086] S3. Based on the pipeline of the new blast furnace composite injection simulation experimental device, the experimental oxygen volume and experimental hot air volume are obtained. Based on the oxygen-carbon atomic ratio and the volume ratio of oxygen and hydrogen-rich gas, the experimental pulverized coal injection amount, experimental hydrogen-rich gas injection amount, oxygen volume fraction and nitrogen gas integral number in the experimental carrier gas are calculated under the experimental conditions.

[0087] The formula for calculating the amount of pulverized coal injected in the experiment is as follows: In the formula, M coal-exp For the experimental pulverized coal injection rate, kg; n C-exp The molar amount of carbon under experimental conditions, in mol / s. Where, n O-exp The molar amount of oxygen under experimental conditions, in mol / s. In the formula, The volume of oxygen in the experiment, m 3 V hw-fixed The volume of the experimental hot air is m. 3 ;

[0088] Formula for calculating the amount of hydrogen-rich gas injected in the experiment: In the formula, V NG-exp To test the amount of hydrogen-rich gas injected, m 3 ;

[0089] Formula for calculating the volume fraction of oxygen in the experimental carrier gas: In the formula, The oxygen volume fraction, in % (including carrier gas);

[0090] Formula for calculating the nitrogen gas integral: In the formula, The percentage of nitrogen gas including carrier gas;

[0091] The elemental analysis results of the coal sample used in the experiment (i.e., the blast furnace pulverized coal sample) are shown in the table below:

[0092] Table 2 Elemental analysis results of the coal samples used in the experiment

[0093] Coal sample number C H O N S Coal1 83.14％ 3.972％ 0.527％ 2.215％ 0.356％

[0094] From the aforementioned calculation results and Table 2, we can obtain: W hw-fixed =2.46298×10 -4 m 3 n O-exp =0.0149mol, n C-exp =0.00585mol, M coal-exp =0.00008780kg, V NG-exp =0.00002428m 3 ,

[0095] S4. Based on the experimental pulverized coal injection amount, experimental hydrogen-rich gas injection amount, oxygen volume fraction and nitrogen gas integral number in the experimental carrier gas obtained in step S3, conduct the experiment in the new type of blast furnace composite injection simulation experimental device, and calculate the combustion rate based on the results of the gas analyzer.

[0096] Three experiments were conducted in a novel blast furnace composite injection simulation device based on the above experimental parameters. The composition of the gases generated after combustion was analyzed using a gas analyzer, and the results are shown in the table below:

[0097] Table 3 Composition of Combustion Products

[0098] Serial Number CO <![CDATA[CO2]]> <![CDATA[H2]]> <![CDATA[O2]]> 1 1.05％ 15.10％ 0.36％ 33.78％ 2 1.22％ 15.12％ 0.23％ 33.33％ 3 1.03％ 15.17％ 0.55％ 33.99％

[0099] The formula for calculating the combustion rate is as follows:

[0100]

[0101] In the formula: X CO The values ​​are the mole fractions of CO2 and CO generated from the combustion of 0.1g of pulverized coal, as measured by a gas analyzer. Theoretically, this represents the mole fraction of CO2 generated from the complete combustion of carbon in pulverized coal and hydrogen-rich gas.

[0102] in, The calculation method is as follows: In the formula, N is the molar amount of N mol coal powder and carbon in hydrogen-rich gas that is completely converted into CO2; Q includes the molar amount of gas decomposed from coal powder and hydrogen-rich gas as measured by the gas analyzer; L is L mol of gas, including gas that enters the gas collecting bottle before contacting coal powder and gas that collides and mixes with coal powder during injection; it should be noted that the gas decomposed from coal powder and hydrogen-rich gas includes hydrogen, oxygen and nitrogen decomposed from coal powder, and CO and hydrogen decomposed from hydrogen-rich gas.

[0103] Where N = n C +n CH4 n C n is the molar amount of carbon in pulverized coal. CH4 To determine the molar amount of CH4 in the hydrogen-rich gas being injected in the experiment, V 富氢气体 To test the amount of hydrogen-rich gas injected, W CH4 The mass fraction of CH4 in the hydrogen-rich gas injected in the experiment;

[0104] The calculation structure of the combustion rate obtained from the three experiments is shown in the table below:

[0105] Table 4. Calculation results of combustion rate

[0106]

[0107] As shown in the table, the repeatability test of the pulverized coal combustion rate of the hydrogen-rich blast furnace using this simulation test method yielded results with little difference, indicating that the experimental data is relatively accurate. This data has certain reference value for the actual operation of the hydrogen-rich blast furnace and can be used to adjust the actual operating conditions of the hydrogen-rich blast furnace based on the combustion rate.

[0108] In summary, the method for simulating and testing the pulverized coal combustion rate at the tuyere of a hydrogen-rich blast furnace provided by this invention determines the amount of hydrogen-rich gas injected at a single tuyere, the amount of pulverized coal injected, the amount of oxygen injected, and the amount of carrier gas injected based on the actual blast furnace process parameters. This allows for the calculation of the molar amount of carbon atoms, the molar amount of oxygen atoms, the oxygen-carbon ratio, and the volume ratio of oxygen to hydrogen-rich gas at a single tuyere. Furthermore, by combining the pipeline of a novel blast furnace composite injection simulation experimental device, the experimental oxygen volume and experimental hot blast volume are obtained, thereby calculating the amount of pulverized coal injected, the amount of hydrogen-rich gas, the oxygen volume fraction in the carrier gas, and the nitrogen gas integral number under the experimental conditions. Finally, the experiment is conducted in the experimental device based on the obtained experimental parameters, and the combustion rate is calculated based on the results of the gas analyzer. This invention establishes the relationship between pulverized coal injection and the carbon-oxygen atomic ratio through mathematical derivation, and calculates the amount of pulverized coal injected in the experiment. Relying on a novel blast furnace composite injection simulation experimental device, it calculates the injection volume of hydrogen-rich gas and the volume fraction of oxygen and nitrogen in the carrier gas under experimental conditions through relevant blast furnace injection parameters. By simulating the behavior of pulverized coal injection into the furnace and its combustion process in an actual blast furnace in the experimental device, it accurately reflects the actual combustion rate of pulverized coal at the tuyeres of a hydrogen-rich blast furnace, which has important guiding significance for the actual production of hydrogen-rich blast furnaces.

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace, characterized in that, Includes the following steps: S1. Determine the amount of hydrogen-rich gas injected through a single tuyer, the amount of coal injected through a single tuyer, the amount of oxygen-rich gas injected through a single tuyer, and the amount of carrier gas injected through a single tuyer based on the actual process parameters of the blast furnace. S2. Determine the molar amount of carbon atoms in a single vent by the amount of coal injected into a single vent as described in step S1, and determine the molar amount of oxygen atoms in a single vent by the amount of oxygen-enriched gas injected into a single vent, thereby obtaining the oxygen-carbon ratio; obtain the volume ratio of oxygen and hydrogen-enriched gas by the amount of oxygen-enriched gas injected into a single vent and the amount of hydrogen-enriched gas injected into a single vent. S3. Based on the pipeline of the new blast furnace composite injection simulation experimental device, the experimental oxygen volume and experimental hot air volume are obtained. Based on the oxygen-carbon atomic ratio and the volume ratio of oxygen and hydrogen-rich gas, the experimental pulverized coal injection amount, experimental hydrogen-rich gas injection amount, oxygen volume fraction and nitrogen gas integral number in the experimental carrier gas are calculated under the experimental conditions. S4. Based on the experimental pulverized coal injection rate, experimental hydrogen-rich gas injection rate, oxygen volume fraction in the experimental carrier gas, and nitrogen gas integral number obtained in step S3, conduct experiments in the novel blast furnace composite injection simulation experimental device, and calculate the combustion rate based on the results of the gas analyzer; the formula for calculating the combustion rate is as follows: In the formula: , These are the mole fractions of CO2 and CO generated from the combustion of 0.1g of pulverized coal, as measured by the gas analyzer. Theoretically, this represents the mole fraction of CO2 generated from the complete combustion of carbon in pulverized coal and hydrogen-rich gas. in, The calculation method is as follows: In the formula, N is the molar amount of N mol coal powder and carbon in hydrogen-rich gas that is completely converted into CO2; Q includes the molar amount of coal powder and decomposed gas in hydrogen-rich gas as measured by the gas analyzer; L is L mol gas, including gas that has not been in contact with coal powder and has entered the gas collecting bottle beforehand, as well as gas that has collided and mixed with coal powder during injection. in, , n C This represents the molar amount of carbon in pulverized coal. n CH4 To determine the molar amount of CH4 in the hydrogen-rich gas being injected in the experiment, , V 富氢气体 The amount of hydrogen-rich gas injected in the experiment is [amount missing]. The mass fraction of CH4 in the hydrogen-rich gas injected in the experiment.

2. The method of simulating the hydrogen-rich blast furnace tuyere coal powder combustion rate according to claim 1, characterized in that, In step S1, the actual process parameters of the blast furnace include the amount of hydrogen-rich gas injected into the blast furnace, the blast furnace coal ratio, the blast furnace molten iron production rate, the blast furnace blast volume, the oxygen enrichment rate, and the amount of pulverized coal carrier gas injected.

3. The method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace according to claim 2, characterized in that, The formula for calculating the amount of hydrogen-rich gas injected through a single air outlet is as follows: In the formula, The amount of hydrogen-rich gas injected from a single air outlet, m 3 / s, The amount of hydrogen-rich gas injected into the blast furnace per minute, m 3 / min, This refers to the number of blast furnace tuyeres. The formula for calculating the coal injection rate at a single air outlet is as follows: In the formula, The coal injection rate per tuyer is kg / s. The blast furnace coal ratio is expressed in kg / t. The blast furnace hot metal production rate is expressed in t / h. The formula for calculating the oxygen enrichment capacity of a single air outlet is as follows: In the formula, For single-outlet oxygen enrichment, m 3 / s, For blast furnace blast volume, m 3 / min, Oxygen enrichment rate, % The formula for calculating the carrier air volume injected through a single air outlet is as follows: In the formula, For single-nozzle injection of carrier air, m 3 / s, For pulverized coal gas carrier gas volume, m 3 / min.

4. The method of simulating the hydrogen-rich blast furnace tuyere coal powder combustion rate according to claim 3, characterized in that, In step S2, The formula for calculating the molar amount of carbon atoms in a single air outlet is: In the formula, The molar amount of carbon atoms per vent, in mol / s. The carbon content of pulverized coal is fixed at % %. The calculation formula of the single tuyere oxygen atom molar quantity is: , wherein, is the single tuyere oxygen atom molar quantity, mol / s; The formula for calculating the oxygen-carbon atomic ratio is: , wherein is the oxygen-carbon atomic ratio; The volume ratio of the oxygen and hydrogen-rich gas is calculated by the formula: wherein is the volume ratio of the oxygen and hydrogen-rich gas.

5. The method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace according to claim 4, characterized in that, In step S3, The formula for calculating the amount of pulverized coal injected in the experiment is as follows: , In the formula, The amount of pulverized coal injected in the experiment is in kg; The molar amount of carbon under experimental conditions, in mol / s. ,in, The molar amount of oxygen under experimental conditions, in mol / s. In the formula, The volume of oxygen in the experiment, m 3 , The volume of the experimental hot air is m. 3 ; The formula for calculating the amount of hydrogen-rich gas injected in the experiment is as follows: In the formula, To test the amount of hydrogen-rich gas injected, m 3 ; The formula for calculating the volume fraction of oxygen in the experimental carrier gas is as follows: In the formula, The oxygen volume fraction, including carrier gas, is expressed as % . The formula for calculating the nitrogen gas volume fraction is: , is the nitrogen gas volume fraction containing the carrier gas amount, %.

6. The method for simulating and testing the pulverized coal combustion rate at the tuyeres of a hydrogen-rich blast furnace according to claim 1, characterized in that, The gases decomposed in the pulverized coal and hydrogen-rich gas include hydrogen, oxygen, and nitrogen from the decomposition of pulverized coal, and CO and hydrogen from the decomposition of hydrogen-rich gas.

7. The method of simulating the hydrogen-rich blast furnace tuyere coal powder combustion rate according to claim 1, characterized in that, In step S3 or step S4, the novel blast furnace composite injection simulation experimental device includes a combustion furnace, a pulverized coal injection system and a hydrogen-rich gas injection system connected to the combustion furnace.

8. The method of simulating the hydrogen-rich blast furnace tuyere coal powder combustion rate according to claim 7, characterized in that, In step S3, a mixed gas is customized as the experimental carrier gas according to the obtained oxygen volume fraction and nitrogen gas integral number. The experimental carrier gas and pulverized coal that meets the experimental pulverized coal injection amount are injected into the combustion furnace from the pulverized coal injection system. Hydrogen-rich gas is injected into the hydrogen-rich gas injection system according to the experimental pulverized hydrogen gas injection amount to simulate the actual dynamics of pulverized coal at the blast furnace tuyeres.

9. The method of simulating the hydrogen-rich blast furnace tuyere coal powder combustion rate according to claim 7, characterized in that, The novel blast furnace composite injection simulation experimental device also includes a pressure control system, a flow control system, and a vacuum pump, used to control the pressure and flow rate of the gas entering the combustion furnace.

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