Hydrogen production by steam methane reforming

Abstract

This invention belongs to the field of HyCROF smelting technology, specifically disclosing a method for multi-media matching and stable operation control in a HyCROF furnace. This method sequentially performs system analysis of the multi-media action mechanism, establishes nitrogen standard, determines the optimal dosage of each medium, studies the replacement ratios of pulverized coal with CO / H2 and CO with H2, formulates technical standards and operating procedures, and verifies and optimizes the system. Through simulation experiments, the action mechanisms and critical thresholds of nitrogen, hydrogen, CO, and pulverized coal are clarified; a nitrogen dosage correlation model and dynamic adjustment range are established; orthogonal experiments determine the optimal dosage of each medium and the dynamic adjustment model; and replacement ratio experiments determine the benchmark replacement ratio and establish a dynamic correction model, ultimately forming a standardized control system. This invention achieves multi-media synergistic matching in the HyCROF smelting system, significantly improving furnace stability and reduction efficiency, reducing energy consumption and production costs, and is applicable to various operating conditions of a 2500HyCROF smelting system.

Description

Technical Field

[0001] This invention relates to the field of HyCROF smelting technology, and in particular to a method for multi-media matching and stable operation control in a HyCROF furnace. Background Technology

[0002] HyCROF smelting technology represents a significant development direction for efficient ironmaking processes. Its core advantage lies in the synergistic participation of multiple media, including nitrogen, hydrogen, CO, and pulverized coal, in redox reactions, thereby improving ironmaking efficiency and optimizing energy consumption. However, in practical industrial applications, this technology suffers from a lack of scientific standards for controlling the proportions of these multiple media, leading to a series of technical bottlenecks. 1. The mechanism of nitrogen action is not clear and there is a lack of quantitative nitrogen standards. Excessive nitrogen will inhibit the efficiency of the reduction reaction, while insufficient nitrogen will not be able to ensure the stability of the furnace pressure, resulting in fluctuations in system operation. 2. There is no precise matching basis for the dosage of each medium, the synergistic effect of hydrogen and CO reduction is not fully utilized, the coal powder combustion efficiency does not match the reduction reaction requirements, resulting in energy waste and low reaction efficiency. 3. There is a lack of systematic research on the replacement ratio among pulverized coal, CO, and H2, resulting in high media consumption costs and an inability to dynamically adjust the replacement ratio according to furnace conditions; 4. Imbalance in the proportion of multiple media leads to insufficient oxidation-reduction reaction, uneven distribution of temperature and concentration fields in the furnace, resulting in furnace condition fluctuations, unstable molten iron quality, and in severe cases, abnormal conditions such as material suspension and material collapse.

[0003] The aforementioned problems are interconnected and form a vicious cycle, severely restricting the stable operation and efficiency improvement of the HyCROF smelting system. Therefore, it is urgent to establish a scientific and precise multi-media matching control method, clarify the action mechanism of each medium, optimize the dosage ratio, determine the replacement ratio standard, and solve the defects of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to provide a method for multi-media matching and stable operation control in a HyCROF furnace, so as to solve the problems of disordered multi-media ratio, unstable operation and high energy consumption in the prior art, and realize the efficient, stable and low-cost operation of the HyCROF smelting system.

[0005] To achieve the above objectives, the basic solution provided by this invention is: a method for multi-media matching and stable operation control in a HyCROF furnace, comprising the following steps: S1: Multi-media reaction mechanism system analysis: A multi-media reaction simulation platform was built in the HyCROF furnace to simulate the redox reactions of nitrogen, hydrogen, CO with iron ore at 1200-1500℃ and 0.3-0.6MPa. Changes in gas composition were monitored, and thermodynamic calculations were combined to clarify the patterns of hydrogen dominating reduction in the high-temperature region of 1350-1500℃, CO dominating reduction in the low-temperature region of 1200-1350℃, and nitrogen not participating in reduction but influencing the pressure field and gas velocity distribution within the furnace. A single-factor variable experiment for nitrogen was designed, with nitrogen concentration gradients of 0-500 Nm. 3 / h, with other medium parameters being hydrogen 100-150Nm 3 / h, CO200-250Nm 3 / h, pulverized coal injection rate 50-80kg / t iron, monitor furnace pressure, reduction efficiency, and changes in molten iron composition to determine the critical threshold for nitrogen action; S2: Establishment of Nitrogen Allocation Standards: Based on the S1 experimental data, combined with the furnace pressure control requirement of 0.4-0.5 MPa and the efficiency target of ≥95% reduction, a multi-objective optimization algorithm was used to establish a nitrogen allocation correlation model: Where N2 is the amount of nitrogen supplied (Nm 3 / h), where P is the target pressure inside the furnace (MPa). To determine the reduction efficiency (%), the dynamic adjustment range of nitrogen dosage was determined, a standard operating procedure for nitrogen dosage was established, and the initial set value, dynamic adjustment trigger conditions, adjustment range, and monitoring frequency of once every 15 minutes were clarified. S3: Determination of optimal dosage for each medium: An orthogonal experimental design was adopted, selecting nitrogen dosages of 150, 200, 250, and 300 Nm³. 3 / h, hydrogen 100, 120, 140, 160 Nm 3 / h, CO 200, 220, 240, 260Nm 3 Using the pulverized coal injection rate of 50, 60, 70, and 80 kg / t iron as experimental factors, and reduction efficiency, molten iron quality, and energy consumption as evaluation indicators, 16 orthogonal experiments were designed. Industrial tests were conducted, and the influence weights of each factor were determined through range and variance analysis. The optimal dosage range of each medium was determined by combining a multi-objective optimization model, and a dynamic adjustment model for the dosage of the medium based on changes in raw material composition and furnace temperature was established. S4: Study on the replacement ratio of pulverized coal, CO, and H2: With a fixed reduction efficiency ≥95% and molten iron quality standard, single-medium replacement tests were conducted for CO replacing pulverized coal, H2 replacing pulverized coal, and H2 replacing CO, respectively. The media increment when the reduction efficiency stabilized was recorded, and the baseline replacement ratio between each medium was calculated. Replacement ratio tests were carried out under different furnace conditions, and the CO to pulverized coal replacement ratio of 4-5 Nm was determined through statistical analysis. 3 / kg, H2 to pulverized coal replacement ratio 2-3Nm 3 / kg, H2 to CO replacement ratio 0.5-0.6 Nm 3 / Nm 3 Establish a dynamic correction model for the replacement ratio that takes into account the cost of the medium and the furnace condition parameters; S5: Technical Standards and Operating Procedures Development: Integrate the research results of S2-S4, develop the "HyCROF In-furnace Multi-media Matching Technical Standard", compile operating procedures including initial setting of media usage, dynamic adjustment, replacement operation, and abnormal handling, and establish a quality traceability system; S6: System Validation and Optimization: Conduct 3 months of industrial application validation in the 2500HyCROF smelting system, monitor reduction efficiency, molten iron quality, media consumption, and furnace stability indicators, and revise and optimize nitrogen standard, optimal media dosage, and replacement ratio model based on validation data, and establish a continuous improvement mechanism.

[0006] Furthermore, the dynamic adjustment range of nitrogen dosage mentioned in S2 is: 150-300 Nm³ under normal furnace conditions. 3 / h; when the furnace pressure is below 0.4MPa, use 50Nm 3 The nitrogen concentration is increased gradually in a gradient of / h, but should not exceed 400 Nm. 3 / h; when the reduction efficiency is less than 90%, use 30Nm 3 The nitrogen content should be gradually reduced in a gradient of / h, with a minimum of 80 Nm. 3 / h; the dynamic adjustment trigger conditions are pressure fluctuation ±0.02MPa and reduction efficiency fluctuation ±2%.

[0007] Furthermore, the optimal dosage range for each medium mentioned in S3 is: nitrogen 180-250 Nm³. 3 / h, corresponding to an internal furnace pressure of 0.42-0.48MPa; hydrogen 120-150Nm 3 / h, corresponding to a reduction efficiency of ≥96% in the high-temperature zone; CO2 20-250Nm 3 / h, corresponding to a reduction efficiency of ≥94% in the medium and low temperature zone; pulverized coal injection rate of 60-75kg / t iron, corresponding to a coal ratio of ≤70kg / t iron.

[0008] Furthermore, the adjustment rule of the dynamic adjustment model for the amount of medium used described in S3 is as follows: when the TFe content of iron ore decreases by 1%, the amount of hydrogen used increases by 5 Nm. 3 / h, increase pulverized coal injection rate by 3 kg / t iron; when the furnace temperature rises by 50℃, reduce CO dosage by 10 Nm 3 / h, nitrogen usage increased by 20 Nm 3 / h.

[0009] Furthermore, the adjustment rules of the replacement ratio dynamic correction model described in S4 are as follows: when the price of pulverized coal increases by 10%, the replacement ratio is increased by 5% and the substitution ratio of CO and H2 is increased; when the furnace temperature is below 1300℃, the replacement ratio is increased by 8% and the proportion of H2 replacing CO is increased.

[0010] Furthermore, the continuous improvement mechanism described in S6 involves regularly collecting production data and dynamically updating the "HyCROF In-furnace Multi-media Matching Technology Standard" and operating procedures in conjunction with technological advancements and changes in raw material composition.

[0011] Compared with the prior art, the advantages of this invention are: 1. The mechanism of action of each medium and the nitrogen standard were clarified, which solved the problem of disordered nitrogen mixing. The pressure fluctuation range inside the furnace was reduced from ±0.05MPa to ±0.02MPa, the reduction efficiency was improved by 3-5%, and the furnace condition stability was effectively guaranteed.

[0012] 2. The optimal dosage ratio of each medium has been optimized to achieve synergistic and efficient participation of multiple media in the redox reaction, reducing coal powder consumption by 8-10 kg / t iron and increasing CO and H2 utilization by 5-7%, significantly reducing energy consumption and production costs.

[0013] 3. A scientific replacement ratio standard and dynamic correction model have been established, which can flexibly adjust the replacement strategy according to changes in medium price and furnace condition, and reduce the production cost of a single furnace by 3-5 yuan / t of iron.

[0014] 4. A complete set of technical standards and operating procedures have been established. Standardized operation reduces human error, and the pass rate has increased from 85% to 98%. The quality traceability system provides data support for subsequent optimization and improves the level of production management.

[0015] 5. The method is highly adaptable and can dynamically adjust parameters according to factors such as raw material composition and furnace condition changes. It is applicable to 2500HyCROF smelting systems under different working conditions, providing technical support for the large-scale promotion and application of HyCROF technology. Detailed Implementation

[0016] The present invention will be further described in detail below through specific embodiments: A method for multi-media matching and stable operation control in a HyCROF furnace includes the following steps: S1: Multi-media reaction mechanism system analysis: A multi-media reaction simulation platform was built in the HyCROF furnace to simulate the redox reactions of nitrogen, hydrogen, CO with iron ore at 1200-1500℃ and 0.3-0.6MPa. Changes in gas composition were monitored, and thermodynamic calculations were combined to clarify the patterns of hydrogen dominating reduction in the high-temperature region of 1350-1500℃, CO dominating reduction in the low-temperature region of 1200-1350℃, and nitrogen not participating in reduction but influencing the pressure field and gas velocity distribution within the furnace. A single-factor variable experiment for nitrogen was designed, with nitrogen concentration gradients of 0-500 Nm. 3 / h, with other medium parameters being hydrogen 100-150Nm 3 / h, CO200-250Nm 3 / h, pulverized coal injection rate 50-80kg / t iron, monitor furnace pressure, reduction efficiency, and changes in molten iron composition to determine the critical threshold for nitrogen action; S2: Establishment of Nitrogen Allocation Standards: Based on the S1 experimental data, combined with the furnace pressure control requirement of 0.4-0.5 MPa and the efficiency target of ≥95% reduction, a multi-objective optimization algorithm was used to establish a nitrogen allocation correlation model: Where N2 is the amount of nitrogen supplied (Nm 3 / h), where P is the target pressure inside the furnace (MPa). To determine the reduction efficiency (%), the dynamic adjustment range of nitrogen dosage was established, and a standard operating procedure for nitrogen dosage was set, specifying the initial set value, dynamic adjustment trigger conditions, adjustment range, and monitoring frequency every 15 minutes. A method for multi-media matching and stable operation control in a HyCROF furnace was proposed, with the nitrogen dosage dynamically adjusted within the range of 150-300 Nm³ under normal furnace conditions. 3 / h; when the furnace pressure is below 0.4MPa, use 50Nm 3 The nitrogen concentration is increased gradually in a gradient of / h, but should not exceed 400 Nm. 3 / h; when the reduction efficiency is less than 90%, use 30Nm 3 The nitrogen content should be gradually reduced in a gradient of / h, with a minimum of 80 Nm. 3 / h; the dynamic adjustment trigger conditions are pressure fluctuation ±0.02MPa and reduction efficiency fluctuation ±2%; S3: Determination of optimal dosage for each medium: An orthogonal experimental design was adopted, selecting nitrogen dosages of 150, 200, 250, and 300 Nm³. 3 / h, hydrogen 100, 120, 140, 160 Nm 3 / h, CO 200, 220, 240, 260Nm 3Using the pulverized coal injection rate of 50, 60, 70, and 80 kg / t iron as experimental factors, and reduction efficiency, molten iron quality, and energy consumption as evaluation indicators, 16 orthogonal experiments were designed. Industrial trials were conducted, and the influence weights of each factor were determined through range and variance analysis. The optimal dosage range for each medium was determined using a multi-objective optimization model, and a dynamic adjustment model for medium dosage based on changes in raw material composition and furnace temperature was established. A method for multi-medium matching and stable operation control in a HyCROF furnace was developed, with the optimal dosage range for each medium being: nitrogen 180-250 Nm³. 3 / h, corresponding to an internal furnace pressure of 0.42-0.48MPa; hydrogen 120-150Nm 3 / h, corresponding to a reduction efficiency of ≥96% in the high-temperature zone; CO2 20-250Nm 3 / h, corresponding to a reduction efficiency ≥94% in the medium and low temperature zone; pulverized coal injection rate 60-75kg / t iron, corresponding to a coal ratio ≤70kg / t iron; the adjustment rule of the dynamic adjustment model of the medium usage in a HyCROF furnace multi-media matching and stable operation control method is: when the TFe content of iron ore decreases by 1%, the hydrogen usage increases by 5Nm 3 / h, increase pulverized coal injection rate by 3 kg / t iron; when the furnace temperature rises by 50℃, reduce CO dosage by 10 Nm 3 / h, nitrogen usage increased by 20 Nm 3 / h.

[0017] S4: Study on the replacement ratio of pulverized coal, CO, and H2: With a fixed reduction efficiency ≥95% and molten iron quality standard, single-medium replacement tests were conducted for CO replacing pulverized coal, H2 replacing pulverized coal, and H2 replacing CO, respectively. The media increment when the reduction efficiency stabilized was recorded, and the baseline replacement ratio between each medium was calculated. Replacement ratio tests were carried out under different furnace conditions, and the CO to pulverized coal replacement ratio of 4-5 Nm was determined through statistical analysis. 3 / kg, H2 to pulverized coal replacement ratio 2-3Nm 3 / kg, H2 to CO replacement ratio 0.5-0.6 Nm 3 / Nm 3 A dynamic correction model for the replacement ratio considering media costs and furnace condition parameters was established. The adjustment rule of the dynamic correction model for the replacement ratio of a HyCROF furnace multi-media matching and stable operation control method is as follows: when the price of pulverized coal increases by 10%, the replacement ratio is increased by 5% and the substitution ratio of CO and H2 is increased; when the furnace temperature is below 1300℃, the replacement ratio is increased by 8% and the proportion of H2 replacing CO is increased. S5: Technical Standards and Operating Procedures Development: Integrate the research results of S2-S4, develop the "HyCROF In-furnace Multi-media Matching Technical Standard", compile operating procedures including initial setting of media usage, dynamic adjustment, replacement operation, and abnormal handling, and establish a quality traceability system; S6: System Validation and Optimization: A 3-month industrial application validation was conducted in the 2500HyCROF smelting system, monitoring reduction efficiency, molten iron quality, media consumption, and furnace stability indicators. Based on the validation data, the nitrogen formulation standard, optimal media dosage, and replacement ratio model were revised and optimized to establish a continuous improvement mechanism. A continuous improvement mechanism for the HyCROF furnace multi-media matching and stable operation control method involves periodically collecting production data and dynamically updating the "HyCROF Furnace Multi-Media Matching Technology Standard" and operating procedures in conjunction with technological developments and changes in raw material composition.

[0018] The specific implementation plan for the above control method is as follows: 1. Multi-media interaction mechanism analysis experiment Monitoring points were set up in the lower part of the HyCROF furnace body (medium and low temperature zone 1200-1350℃) and the furnace belly (high temperature zone 1350-1500℃), and pressure sensors, temperature sensors and gas sampling devices were installed and connected to gas chromatograph and infrared spectrometer. The initial furnace pressure was set to 0.45MPa, the temperature to 1350℃, the iron ore loading was calculated based on the designed capacity of 5500t / d, and the coke loading was set based on a coke ratio of 350kg / t iron.

[0019] Nitrogen gas set at 200 Nm 3 / h, hydrogen 130Nm 3 / h、CO230Nm 3 With a coal powder injection rate of 65 kg / t iron, the smelting system was started and operated continuously for 4 hours. Gas samples were collected every 30 minutes to analyze the changes in gas concentration and calculate the reduction reaction rate.

[0020] Maintain hydrogen at 130 Nm 3 / h、CO230Nm 3 With the coal powder injection rate remaining constant at 65 kg / t iron, nitrogen dosages are set at 100, 150, 200, 250, 300, 350, and 400 Nm³ respectively. 3 / h, each nitrogen dosage is run for 2 hours, and the furnace pressure, reduction efficiency and Si content of molten iron are monitored; the monitoring data are shown in Table 1.

[0021] Table 1: Monitoring Data Table The test results show that the nitrogen content is between 180-250 Nm³. 3 When the furnace pressure is constant at 0.42-0.48 MPa, the reduction efficiency is maintained at 94.9-95.8%, the molten iron quality is stable, and the positive effect of nitrogen is dominant.

[0022] 2. Establishment and Implementation of Nitrogen Standards Based on experimental data, the least squares method was used to fit the correlation model of nitrogen dosage. Substituting the target pressure of 0.42-0.48 MPa and the reduction efficiency of 94.9-95.8%, the calculated nitrogen dosage range is 180-250 Nm³. 3 / h.

[0023] Establish nitrogen standard: initial setting value 200 Nm 3 / h (corresponding to a pressure of 0.45MPa and a reduction efficiency of 95.5%); the adjustment trigger condition is that the furnace pressure fluctuation exceeds ±0.02MPa or the reduction efficiency fluctuation exceeds ±2%; the adjustment increment is 30Nm each time when the pressure is below 0.43MPa. 3 / h, when the pressure is higher than 0.47MPa, reduce by 30Nm each time. 3 / h, when the reduction efficiency is below 93.5%, decrease by 20Nm each time. 3 / h, with a reduction efficiency higher than 97.5%, each increment is 20 Nm 3 / h; The monitoring frequency is to record the furnace pressure and reduction efficiency every 15 minutes, and analyze the gas composition every hour.

[0024] After inputting the nitrogen standard parameters into the central control system and starting the automatic control program, when the furnace pressure drops to 0.42 MPa, the system automatically increases the nitrogen quantity by 30 Nm³. 3 / h to 230Nm 3 The system operates at a stable pressure of 0.45 MPa per hour; when the reduction efficiency drops to 93.4%, the system automatically reduces the nitrogen dosage by 20 Nm³. 3 / h to 180Nm 3 After the reduction efficiency recovered to 94.9% per hour, it stabilized.

[0025] 3. Determination of the optimal dosage of each medium Experimental design: Nitrogen, hydrogen, CO, and pulverized coal injection rate were selected as experimental factors, with four levels for each factor, using an L16 (4) experimental design. 4 Sixteen experimental schemes were designed using orthogonal arrays, as shown in Table 2.

[0026] Table 2: Orthogonal Table of Experimental Designs Experimental implementation: Each group of experiments ran for 24 hours, and data such as reduction efficiency, Si content and S content in molten iron and total medium consumption were recorded. The energy consumption per unit of molten iron was calculated, and the experimental results are shown in Table 3.

[0027] Table 3: Experimental Results Data processing: Range analysis revealed the degree of influence of each factor on reduction efficiency: hydrogen > CO > nitrogen > pulverized coal; the degree of influence on energy consumption per unit of molten iron: pulverized coal > hydrogen > CO > nitrogen. Combined with multi-objective optimization, the optimal dosage range for each medium was determined: nitrogen 180-250 Nm³. 3 / h, hydrogen 120-150Nm 3 / h, CO2 20-250Nm 3 / h, 60-75kg / t iron pulverized coal.

[0028] Dynamic adjustment model verification: When the TFe content in iron ore decreases from 56% to 55%, the hydrogen consumption is adjusted to 135 Nm. 3 With a coal powder injection rate of 68 kg / t iron per hour, the reduction efficiency remained at 95.5% after operation, verifying the effectiveness of the model.

[0029] 4. Research and Application of Replacement Ratio CO and pulverized coal replacement test: maintain nitrogen at 200 Nm³ 3 / h, hydrogen 130Nm 3 / h remains unchanged, initial pulverized coal 65kg / t iron, CO2 30Nm 3 / h, reduction efficiency 95.5%; reduce pulverized coal to 60kg / t iron, increase CO to 250Nm 3 / h, reduction efficiency 95.3%, displacement ratio 4Nm 3 / kg; continue to reduce pulverized coal to 55kg / t iron, and increase CO to 275Nm 3 / h, reduction efficiency 95.1%, displacement ratio 5Nm 3 / kg, determine the CO to pulverized coal replacement ratio of 4-5 Nm 3 / kg.

[0030] H2 and pulverized coal replacement test: maintain nitrogen at 200 Nm³ 3 / h、CO230Nm 3 / h remains unchanged, initial pulverized coal 65kg / t iron, H2 130Nm 3 / h, reduction efficiency 95.5%; reduce pulverized coal to 60kg / t iron, increase H2 to 140Nm 3 / h, reduction efficiency 95.4%, displacement ratio 2Nm 3 / kg; reduce pulverized coal to 55kg / t iron, increase H2 to 155Nm 3 / h, reduction efficiency 95.2%, displacement ratio 3Nm 3 / kg, determine the H2 to pulverized coal replacement ratio 2-3Nm 3 / kg.

[0031] H2 and CO replacement test: maintain nitrogen gas at 200 Nm³. 3 / h, pulverized coal 65kg / t iron constant, initial CO2 30Nm 3 / h、H2130Nm 3 / h, reduction efficiency 95.5%; CO reduced to 220Nm 3 / h, increase H2 to 135Nm 3 / h, reduction efficiency 95.4%, displacement ratio 0.5Nm 3 / Nm 3 Reduce CO to 210 Nm 3 / h, increase H2 to 141Nm 3 / h, reduction efficiency 95.3%, displacement ratio 0.6Nm 3 / Nm 3 The H2 to CO replacement ratio was determined to be 0.5-0.6 Nm. 3 / Nm 3 .

[0032] Application of the replacement strategy: When the price of pulverized coal increases by 10%, adjust the replacement ratio to the upper limit, reduce the pulverized coal injection rate by 5 kg / t iron, and increase CO by 25 Nm³. 3 / h, H2 increased by 15Nm 3 / h, the unit cost of molten iron is reduced by 4.2 yuan / t; when the furnace temperature drops to 1300℃, the H2 to CO replacement ratio is increased to 0.65Nm 3 / Nm 3 Increase H2 usage by 10 Nm 3 / h, reduce CO usage by 15Nm 3 / h, the furnace temperature rises to 1350℃, and the reduction efficiency remains stable.

[0033] 5. Implementation and verification of technical standards We developed the "HyCROF Furnace Multi-Media Matching Technology Standard" and operating procedures, and provided professional training to operators to ensure they were proficient in nitrogen matching standards, media dosage adjustment methods, and replacement operation procedures.

[0034] This method was fully implemented in the 2500HyCROF smelting system and operated continuously for 3 months. The key indicators monitored were as follows: the average reduction efficiency was 95.2%, an increase of 4.3% compared with before implementation; the furnace pressure fluctuation was ±0.02MPa, a decrease of 60% compared with before implementation; the average coal powder consumption was 68kg / t iron, a decrease of 9kg / t iron compared with before implementation; the average unit energy consumption was 505kgce / t iron, a decrease of 35kgce / t iron compared with before implementation; and the Si content fluctuation in molten iron was ±0.03%, a decrease of 50% compared with before implementation.

[0035] Based on the verification data, the method was optimized and adjusted: the initial setting value of the nitrogen standard was adjusted to 210 Nm. 3 / h, the optimal hydrogen usage range is adjusted to 125-145Nm 3 / h, further improving furnace stability and energy utilization efficiency.

[0036] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for multi-media matching and stable operation control in a HyCROF furnace, characterized in that, Includes the following steps: S1: Multi-media reaction mechanism system analysis: A multi-media reaction simulation platform was built in the HyCROF furnace to simulate the redox reactions of nitrogen, hydrogen, CO with iron ore at 1200-1500℃ and 0.3-0.6MPa. Changes in gas composition were monitored, and thermodynamic calculations were combined to clarify the patterns of hydrogen dominating reduction in the high-temperature region of 1350-1500℃, CO dominating reduction in the low-temperature region of 1200-1350℃, and nitrogen not participating in reduction but influencing the pressure field and gas velocity distribution within the furnace. A single-factor variable experiment for nitrogen was designed, with nitrogen concentration gradients of 0-500 Nm. 3 / h, with other medium parameters being hydrogen 100-150Nm 3 / h, CO200-250Nm 3 / h, pulverized coal injection rate 50-80kg / t iron, monitor furnace pressure, reduction efficiency, and changes in molten iron composition to determine the critical threshold for nitrogen action; S2: Establishment of Nitrogen Allocation Standards: Based on the S1 experimental data, combined with the furnace pressure control requirement of 0.4-0.5 MPa and the efficiency target of ≥95% reduction, a multi-objective optimization algorithm was used to establish a nitrogen allocation correlation model: Where N2 is the amount of nitrogen supplied (Nm 3 / h), where P is the target pressure inside the furnace (MPa). To determine the reduction efficiency (%), the dynamic adjustment range of nitrogen dosage was determined, a standard operating procedure for nitrogen dosage was established, and the initial set value, dynamic adjustment trigger conditions, adjustment range, and monitoring frequency of once every 15 minutes were clarified. S3: Determination of optimal dosage for each medium: An orthogonal experimental design was adopted, selecting nitrogen dosages of 150, 200, 250, and 300 Nm³. 3 / h, hydrogen 100, 120, 140, 160 Nm 3 / h, CO 200, 220, 240, 260Nm 3 Using the pulverized coal injection rate of 50, 60, 70, and 80 kg / t iron as experimental factors, and reduction efficiency, molten iron quality, and energy consumption as evaluation indicators, 16 orthogonal experiments were designed. Industrial tests were conducted, and the influence weights of each factor were determined through range and variance analysis. The optimal dosage range of each medium was determined by combining a multi-objective optimization model, and a dynamic adjustment model for the dosage of the medium based on changes in raw material composition and furnace temperature was established. S4: Study on the replacement ratio of pulverized coal, CO, and H2: With a fixed reduction efficiency ≥95% and molten iron quality standard, single-medium replacement tests were conducted for CO replacing pulverized coal, H2 replacing pulverized coal, and H2 replacing CO, respectively. The media increment when the reduction efficiency stabilized was recorded, and the baseline replacement ratio between each medium was calculated. Replacement ratio tests were carried out under different furnace conditions, and the CO to pulverized coal replacement ratio of 4-5 Nm was determined through statistical analysis. 3 / kg, H2 to pulverized coal replacement ratio 2-3Nm 3 / kg, H2 to CO replacement ratio 0.5-0.6 Nm 3 / Nm 3 Establish a dynamic correction model for the replacement ratio that takes into account the cost of the medium and the furnace condition parameters; S5: Technical Standards and Operating Procedures Development: Integrate the research results of S2-S4, develop the "HyCROF In-furnace Multi-media Matching Technical Standard", compile operating procedures including initial setting of media usage, dynamic adjustment, replacement operation, and abnormal handling, and establish a quality traceability system; S6: System Validation and Optimization: Conduct 3 months of industrial application validation in the 2500HyCROF smelting system, monitor reduction efficiency, molten iron quality, media consumption, and furnace stability indicators, and revise and optimize nitrogen standard, optimal media dosage, and replacement ratio model based on validation data, and establish a continuous improvement mechanism.

2. The method for multi-media matching and stable operation control in a HyCROF furnace according to claim 1, characterized in that, The dynamic adjustment range for nitrogen dosage mentioned in S2 is: 150-300 Nm under normal furnace conditions. 3 / h; when the furnace pressure is below 0.4MPa, use 50Nm 3 The nitrogen concentration is increased gradually in a gradient of / h, but should not exceed 400 Nm. 3 / h; when the reduction efficiency is less than 90%, use 30Nm 3 The nitrogen content should be gradually reduced in a gradient of / h, with a minimum of 80 Nm. 3 / h; the dynamic adjustment trigger conditions are pressure fluctuation ±0.02MPa and reduction efficiency fluctuation ±2%.

3. The method for multi-media matching and stable operation control in a HyCROF furnace according to claim 1, characterized in that, The optimal dosage range for each medium mentioned in S3 is: nitrogen 180-250 Nm³. 3 / h, corresponding to an internal furnace pressure of 0.42-0.48MPa; hydrogen 120-150Nm 3 / h, corresponding to a reduction efficiency of ≥96% in the high-temperature zone; CO2 20-250Nm 3 / h, corresponding to a reduction efficiency of ≥94% in the medium and low temperature zone; pulverized coal injection rate of 60-75kg / t iron, corresponding to a coal ratio of ≤70kg / t iron.

4. The method for multi-media matching and stable operation control in a HyCROF furnace according to claim 1, characterized in that, The adjustment rule of the dynamic adjustment model for medium usage described in S3 is as follows: when the TFe content of iron ore decreases by 1%, the hydrogen usage increases by 5 Nm. 3 / h, increase pulverized coal injection rate by 3 kg / t iron; when the furnace temperature rises by 50℃, reduce CO dosage by 10 Nm 3 / h, nitrogen usage increased by 20 Nm 3 / h.

5. The method for multi-media matching and stable operation control in a HyCROF furnace according to claim 1, characterized in that, The adjustment rules of the replacement ratio dynamic correction model described in S4 are as follows: when the price of pulverized coal increases by 10%, the replacement ratio is increased by 5% and the substitution ratio of CO and H2 is increased; when the furnace temperature is below 1300℃, the replacement ratio is increased by 8% and the proportion of H2 replacing CO is increased.

6. The method for multi-media matching and stable operation control in a HyCROF furnace according to claim 1, characterized in that, The continuous improvement mechanism described in S6 involves regularly collecting production data and dynamically updating the "HyCROF In-furnace Multi-media Matching Technology Standard" and operating procedures in conjunction with technological advancements and changes in raw material composition.

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