Method for establishing a hydrogen-rich carbon cycle oxygen blast furnace partitioned heat and mass balance model
By establishing a blast furnace zoned heat and mass balance model, the problem of the lack of mathematical models for hydrogen-rich carbon-cycle oxygen blast furnaces was solved, enabling accurate evaluation and optimization of process parameters and ensuring stable low-carbon production of the blast furnace.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINJIANG BAYI IRON & STEEL CO LTD
- Filing Date
- 2026-03-09
- Publication Date
- 2026-07-21
AI Technical Summary
The lack of precise mathematical models to describe the full-process thermodynamics and material balance of hydrogen-rich carbon-cycle oxygen blast furnaces leads to a lack of quantitative basis for process design and operating procedures, affecting the stability of blast furnace operation and carbon emission control.
A zoned heat and mass balance model for a hydrogen-rich carbon-cycle oxygen blast furnace was established. By dividing the blast furnace into a low-temperature zone and a high-temperature zone, mass conservation, element balance, and enthalpy balance equations were established and solved using an iterative algorithm. Combined with the Lister operating line theory, the furnace working efficiency was defined, and the carbon reduction rate was calculated to evaluate the merits of the process route.
It enables accurate prediction of blast furnace operating status, identifies optimal process parameters, avoids furnace condition fluctuations, guides process optimization, and supports stable and low-carbon blast furnace production.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of blast furnace ironmaking technology, specifically to a method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace. Background Technology
[0002] Blast furnace-converter process is the mainstream steel production technology in my country, accounting for about 15% of the country's total carbon emissions. Of this, the blast furnace ironmaking stage accounts for 70% of the carbon emissions from this process. Under the "dual carbon" target (referring to carbon emissions from both the steel and converter processes), developing hydrogen-rich carbon-recycled oxygen blast furnace technology is a key path for the steel industry to achieve deep carbon reduction. This process, by injecting decarburized recycled gas and hydrogen-rich gas, supplemented by all-oxygen smelting, can significantly reduce solid fuel consumption and carbon emissions.
[0003] However, the hydrogen-rich carbon-recycled oxygen blast furnace is a system involving multiphase flow of gas, solid, and pulverized coal, high-temperature and high-pressure reactions, and complex heat and mass transfer. Even minor variations in process parameters can affect the furnace's thermal balance, reducing atmosphere, gas flow distribution, and ultimately, the yield and quality of molten iron. Currently, there is a lack of a mathematical model that can accurately describe the thermodynamics and material balance of the entire process, resulting in a lack of quantitative basis for process design, operating procedure formulation, and performance evaluation. Summary of the Invention
[0004] The purpose of this invention is to provide a method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-recirculating oxygen blast furnace, in order to solve the problem that the lack of a mathematical model of the thermodynamics and material balance of the entire process currently leads to a lack of quantitative basis for process design, operation system formulation and effect evaluation.
[0005] To achieve the above objectives, the basic solution provided by this invention is: a method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace, comprising the following steps: S1. Along the height of the blast furnace, the blast furnace is divided into a low-temperature zone and a high-temperature zone, with the 950℃ heat reserve zone as the boundary. S2. For the low temperature zone and the high temperature zone, establish the mass conservation equation, element balance equation and enthalpy balance equation for each zone, define the working efficiency of the furnace body, and set the target composition, temperature of molten iron, slag basicity, furnace top gas temperature and total heat loss of the blast furnace. S3. Solve the problem by combining the mass conservation equation, element balance equation, enthalpy balance equation, and constraints using an iterative algorithm; S4. Based on the calculated results, calculate the carbon reduction rate and evaluate the advantages and disadvantages of different process routes.
[0006] The beneficial effects of this invention are as follows: It establishes a zoned heat and mass balance model for hydrogen-rich carbon-circulating oxygen blast furnace process. The model can predict the blast furnace operating status under different combinations of process parameters, clarify the theoretical combustion temperature lower limit and the optimal gas circulation operation window, effectively avoid furnace condition fluctuations, guide on-site process optimization, and provide core theoretical support for achieving stable, low-carbon, and efficient blast furnace production.
[0007] Option 2, which is the preferred option of the basic option, in S2, the low temperature zone: the input is room temperature furnace charge and rising 950°C gas, and the output is falling 950°C metal oxides, carbon and rising furnace top gas; the high temperature zone: the input is hot air injected from the tuyeres, pulverized coal, circulating gas and furnace charge from the low temperature zone, and the output is molten iron, slag and rising 950°C reducing gas.
[0008] Option 3, the preferred option of the basic option, uses the Lister operating line theory in S2 to define the furnace working efficiency, which is used to correlate the composition of the gas at the furnace top with the direct reduction degree in the high-temperature zone. The formula for calculating the furnace working efficiency is as follows: In the formula: η is the furnace working efficiency (%); GS is the molar ratio of oxygen atoms to carbon atoms in the actual operating line; GW is the molar ratio of oxygen atoms to carbon atoms in the chemical equilibrium line.
[0009] Option 4, the preferred option of the basic scheme, has the following mass conservation equations for each partition in S2: Total mass conservation equation in the low-temperature region: In the formula, This refers to the total mass of the furnace charge fed into the furnace at room temperature. This refers to the total mass of the top gas entering the low-temperature zone. To reduce the total mass of the furnace charge entering the high-temperature zone at 950℃; The total mass of the top gas is expressed in kg / tHM. Total mass conservation equation in the high-temperature region: In the formula, The total mass of the material being sprayed from the air outlet; The total mass of the tuyere blower; 1000 is the standard mass of molten iron in tons; The figures represent the output of slag per ton of iron ore; all units are kg / tHM.
[0010] Option 5, the preferred option of the basic scheme, has the following set of element balance equations for each partition in S2: (1) Fe element equilibrium equation Overall Fe balance in the furnace: In the formula, This refers to the total mass of the iron-containing furnace charge entering the furnace. The total iron content of the ore fed into the furnace; The mass fraction of Fe in molten iron; The mass fraction of FeO in the slag; This represents the molar mass ratio of Fe in FeO; Fe equilibrium in the low-temperature region: In the formula, This refers to the mass fraction of Fe2O3 in the furnace charge. This represents the molar mass ratio of Fe in Fe₂O₃; (2) Balance equation for element C In the formula, , This refers to the consumption of coke and pulverized coal. , To fix the mass fraction of carbon in coke and pulverized coal; The mass fraction of carbon in the sprayed material; This represents the mass fraction of carbon in molten iron. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; , These are the molar mass ratios of C in CO2 and CO, respectively. (3) Balance equation of H element In the formula, , This represents the mass fraction of hydrogen in coke and pulverized coal. The mass fraction of hydrogen in the sprayed material; The total moisture content carried in by the material entering the furnace; The molar mass ratio of hydrogen in H2O; This represents the mass fraction of H2 in the top gas. This represents the mass fraction of H2O in the top gas. (4) Balance equation of element O In the formula, The mass fraction of oxygen in the iron-containing furnace charge; The mass fraction of oxygen in the blower air; This represents the mass fraction of oxygen in pulverized coal. The mass fraction of oxygen in the slag; This represents the molar mass ratio of oxygen in H2O. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; This represents the molar mass ratio of oxygen in CO. This represents the molar mass ratio of oxygen in CO2.
[0011] Option 6, the preferred option of the basic scheme, has the following enthalpy balance equations for each partition in S2: Enthalpy balance equation in the low-temperature region In the formula, The total enthalpy of the furnace charge is input into the low-temperature zone; The total enthalpy of the gas input into the low-temperature zone; This represents the total enthalpy of the furnace charge output in the low-temperature zone. This represents the total enthalpy of the gas output from the low-temperature zone. This represents the total heat loss in the low-temperature region; Enthalpy balance equation in high temperature region In the formula, The total enthalpy of the furnace charge input to the high-temperature zone; The total enthalpy of the material being sprayed from the air outlet; The total enthalpy of the blower air / oxygen; The total physical heat of molten iron; The total physical heat of the slag; This represents the total enthalpy of the gas output from the high-temperature zone. This represents the total heat loss in the high-temperature zone; This represents the total thermal effect of chemical reactions in the high-temperature region.
[0012] Option 7, the preferred option of the basic option, uses the following formula to calculate the carbon reduction rate in S4: In the formula, The total carbon input per ton of iron in a hydrogen-rich carbon-cycled oxygen blast furnace, kg / tHM; The total carbon input per ton of iron under traditional blast furnace baseline operating conditions is expressed in kg / tHM. Detailed Implementation
[0013] The present invention will be further described in detail below through specific embodiments: A method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace includes the following steps: S1. Along the height of the blast furnace, the blast furnace is divided into a low-temperature zone and a high-temperature zone, with the 950°C heat reserve zone as the boundary. The input to the low-temperature zone is ambient temperature charge and rising 950°C gas, and the output is descending 950°C metal oxides, carbon, and rising top gas. The input to the high-temperature zone is hot blast injected from the tuyeres, pulverized coal, circulating gas, and charge from the low-temperature zone, and the output is molten iron, slag, and rising 950°C reducing gas. S2. For the low-temperature and high-temperature zones, establish the mass conservation equation, element balance equation, and enthalpy balance equation for each zone. Using the Lister operating line theory, define the furnace operating efficiency to correlate the composition of the furnace top gas with the direct reduction degree in the high-temperature zone. Set the target composition and temperature of the molten iron, slag basicity, furnace top gas temperature, and the total heat loss of the blast furnace. The formula for calculating the furnace operating efficiency is as follows: In the formula: η is the furnace working efficiency (%); GS is the molar ratio of oxygen atoms to carbon atoms in the actual operating line; GW is the molar ratio of oxygen atoms to carbon atoms in the chemical equilibrium line; The mass conservation equations for each partition are as follows: Total mass conservation equation in the low-temperature region: In the formula, This refers to the total mass of the furnace charge fed into the furnace at room temperature. This refers to the total mass of the top gas entering the low-temperature zone. To reduce the total mass of the furnace charge entering the high-temperature zone at 950℃; The total mass of the top gas is expressed in kg / tHM. Total mass conservation equation in the high-temperature region: In the formula, The total mass of the material being sprayed from the air outlet; The total mass of the tuyere blower; 1000 is the standard mass of molten iron in tons; The output of slag per ton of iron ore furnace; The total mass of the top gas in the heat reserve area; all units are kg / tHM. The elemental balance equations for each partition are as follows: (1) Fe element equilibrium equation Overall Fe balance in the furnace: In the formula, This refers to the total mass of the iron-containing furnace charge entering the furnace. The total iron content of the ore fed into the furnace; The mass fraction of Fe in molten iron; The mass fraction of FeO in the slag; This represents the molar mass ratio of Fe in FeO; Fe equilibrium in the low-temperature region: In the formula, This refers to the mass fraction of Fe2O3 in the furnace charge. This represents the molar mass ratio of Fe in Fe₂O₃; (2) Balance equation for element C Overall furnace C balance: In the formula, , This refers to the consumption of coke and pulverized coal. , To fix the mass fraction of carbon in coke and pulverized coal; The mass fraction of carbon in the sprayed material; This represents the mass fraction of carbon in molten iron. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; , These are the molar mass ratios of C in CO2 and CO, respectively. (3) Balance equation of H element In the formula, , This represents the mass fraction of hydrogen in coke and pulverized coal. The mass fraction of hydrogen in the sprayed material; The total moisture content carried in by the material entering the furnace; The molar mass ratio of hydrogen in H2O; This represents the mass fraction of H2 in the top gas. This represents the mass fraction of H2O in the top gas. (4) Balance equation of element O In the formula, The mass fraction of oxygen in the iron-containing furnace charge; The mass fraction of oxygen in the blower air; This represents the mass fraction of oxygen in pulverized coal. The mass fraction of oxygen in the slag; This represents the molar mass ratio of oxygen in H2O. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; This represents the molar mass ratio of oxygen in CO. This represents the molar mass ratio of oxygen in CO2. The enthalpy balance equations for each region are as follows: Enthalpy balance equation in the low-temperature region In the formula, The total enthalpy of the furnace charge is input into the low-temperature zone; The total enthalpy of the gas input into the low-temperature zone; This represents the total enthalpy of the furnace charge output in the low-temperature zone. This represents the total enthalpy of the gas output from the low-temperature zone. This represents the total heat loss in the low-temperature region; Enthalpy balance equation in high temperature region In the formula, The total enthalpy of the furnace charge input to the high-temperature zone; The total enthalpy of the material being sprayed from the air outlet; The total enthalpy of the blower air / oxygen; The total physical heat of molten iron; The total physical heat of the slag; This represents the total enthalpy of the gas output from the high-temperature zone. This represents the total heat loss in the high-temperature zone; This refers to the total heat effect of chemical reactions in the high-temperature region. S3. Solve the problem by combining the mass conservation equation, element balance equation, enthalpy balance equation, and constraints using an iterative algorithm; S4. Based on the calculated results, calculate the carbon reduction rate and evaluate the advantages and disadvantages of different process routes; the formula for calculating the carbon reduction rate is as follows: In the formula, The total carbon input per ton of iron in a hydrogen-rich carbon-cycled oxygen blast furnace, kg / tHM; The total carbon input per ton of iron under traditional blast furnace baseline operating conditions is expressed in kg / tHM.
[0014] Example 2 Known basic parameters Standard for ton of iron: 1000kg of molten iron; molten iron composition: w[Fe]=95%, w[C]=4.5%, w[Si]=0.25%, temperature 1500℃; slag parameters: slag amount per ton of iron 300kg / tHM, basicity 1.1, temperature 1550℃.
[0015] Process constraints: Furnace efficiency η=95%, total furnace heat loss is 500000kJ / tHM, minimum furnace top gas temperature ≥110℃.
[0016] ① Traditional blast furnace benchmark operating conditions The blower is 1200℃ hot air, the coal injection rate is 150 kg / tHM, the coke ratio is 372.8 kg / tHM, the theoretical combustion temperature is 2173℃, the carbon input is 433.7 kg / tHM, and the energy input is 14.42 GJ / tHM.
[0017] ② Evaluation of carbon-cycle oxygen blast furnace process: The hot air was turned off and replaced with room temperature oxygen. The temperature of the decarbonized circulating gas (CO 90%, H2 8%, N2 2%) was set at 1200℃, and its injection rate was gradually increased. Iterative calculations were performed with the constraints of a theoretical combustion temperature of not less than 2000℃ and a furnace top gas temperature of not less than 110℃.
[0018] When the circulating gas injection rate reaches 800 Nm 3 At / tHM, the optimized operating condition was obtained, with a theoretical combustion temperature of 2019℃, a direct reduction degree of 0.151, and a carbon input of 315.9 kg / tHM. Compared to the baseline operating condition, Carbon reduction rate .
[0019] ③ Evaluation of hydrogen-rich carbon-circulating oxygen blast furnace process: Based on ②, hydrogen-rich gas is mixed into the circulating coal gas, 40 Nm 3 / tHM natural gas; iteration is performed with the theoretical combustion temperature not lower than 1900℃ as a constraint.
[0020] Optimized operating conditions were achieved: theoretical combustion temperature 1907℃, direct reduction degree 0.085, and carbon input 292.9 kg / tHM. Compared to the baseline operating conditions, the carbon reduction rate was [missing data]. .
[0021] 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 establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace, characterized in that, Includes the following steps: S1. Along the height of the blast furnace, the blast furnace is divided into a low-temperature zone and a high-temperature zone, with the 950℃ heat reserve zone as the boundary. S2. For the low temperature zone and the high temperature zone, establish the mass conservation equation, element balance equation and enthalpy balance equation for each zone, define the working efficiency of the furnace body, and set the target composition, temperature of molten iron, slag basicity, furnace top gas temperature and total heat loss of the blast furnace. S3. Solve the problem by combining the mass conservation equation, element balance equation, enthalpy balance equation, and constraints using an iterative algorithm; S4. Based on the calculated results, calculate the carbon reduction rate and evaluate the advantages and disadvantages of different process routes.
2. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S2, the low-temperature zone: the input is ambient temperature furnace charge and rising 950°C gas, and the output is falling 950°C metal oxides, carbon, and rising furnace top gas. High-temperature zone: The input consists of hot air injected from the tuyeres, pulverized coal, circulating gas, and furnace charge from the low-temperature zone. The output consists of molten iron, slag, and rising 950°C reducing gas.
3. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S2, the Lister operating line theory is used to define the furnace working efficiency, which is used to correlate the composition of the gas at the furnace top with the direct reduction degree in the high-temperature zone. The formula for calculating the furnace working efficiency is as follows: In the formula: η is the furnace working efficiency (%); GS is the molar ratio of oxygen atoms to carbon atoms in the actual operating line; GW is the molar ratio of oxygen atoms to carbon atoms in the chemical equilibrium line.
4. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S2, the mass conservation equations for each partition are as follows: Total mass conservation equation in the low-temperature region: In the formula, This refers to the total mass of the furnace charge fed into the furnace at room temperature. This refers to the total mass of the top gas entering the low-temperature zone. To reduce the total mass of the furnace charge entering the high-temperature zone at 950℃; The total mass of the top gas is expressed in kg / tHM. Total mass conservation equation in the high-temperature region: In the formula, The total mass of the material being sprayed from the air outlet; The total mass of the tuyere blower; 1000 is the standard mass of molten iron in tons; The figures represent the output of slag per ton of iron ore; all units are kg / tHM.
5. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S2, the element balance equations for each partition are as follows: (1) Fe element equilibrium equation Overall Fe balance in the furnace: In the formula, This refers to the total mass of the iron-containing furnace charge entering the furnace. The total iron content of the ore fed into the furnace; The mass fraction of Fe in molten iron; The mass fraction of FeO in the slag; This represents the molar mass ratio of Fe in FeO; Fe equilibrium in the low-temperature region: In the formula, This refers to the mass fraction of Fe2O3 in the furnace charge. This represents the molar mass ratio of Fe in Fe₂O₃; (2) Balance equation for element C Overall furnace C balance: In the formula, , This refers to the consumption of coke and pulverized coal. , To fix the mass fraction of carbon in coke and pulverized coal; The mass fraction of carbon in the sprayed material; This represents the mass fraction of carbon in molten iron. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; , These are the molar mass ratios of C in CO2 and CO, respectively. (3) Balance equation of H element Overall furnace H balance: In the formula, , This represents the mass fraction of hydrogen in coke and pulverized coal. The mass fraction of hydrogen in the sprayed material; The total moisture content carried in by the material entering the furnace; The molar mass ratio of hydrogen in H2O; This represents the mass fraction of H2 in the top gas. This represents the mass fraction of H2O in the top gas. (4) Balance equation of element O Overall furnace balance: In the formula, The mass fraction of oxygen in the iron-containing furnace charge; The mass fraction of oxygen in the blower air; This represents the mass fraction of oxygen in pulverized coal. The mass fraction of oxygen in the slag; This represents the molar mass ratio of oxygen in H2O. This represents the mass fraction of CO2 in the top gas. The mass fraction of CO in the top gas; This represents the molar mass ratio of oxygen in CO. This represents the molar mass ratio of oxygen in CO2.
6. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S2, the enthalpy balance equations for each partition are as follows: Enthalpy balance equation in the low-temperature region In the formula, The total enthalpy of the furnace charge is input into the low-temperature zone; The total enthalpy of the gas input into the low-temperature zone; This represents the total enthalpy of the furnace charge output in the low-temperature zone. This represents the total enthalpy of the gas output from the low-temperature zone. This represents the total heat loss in the low-temperature region; Enthalpy balance equation in high temperature region In the formula, The total enthalpy of the furnace charge input to the high-temperature zone; The total enthalpy of the material being sprayed from the air outlet; The total enthalpy of the blower air / oxygen; The total physical heat of molten iron; The total physical heat of the slag; This represents the total enthalpy of the gas output from the high-temperature zone. This represents the total heat loss in the high-temperature zone; This represents the total thermal effect of chemical reactions in the high-temperature region.
7. The method for establishing a zoned heat and mass balance model for a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that, In S4, the carbon reduction rate is calculated using the following formula: In the formula, The total carbon input per ton of iron in a hydrogen-rich carbon-cycled oxygen blast furnace, kg / tHM; The total carbon input per ton of iron under traditional blast furnace baseline operating conditions is expressed in kg / tHM.