Containing CO 2 Ironmaking method and system coupling gas with biomass injection

Abstract

The present invention relates to an ironmaking method and system coupling CO2-containing gas with biomass injection, belonging to the technical field of blast furnace smelting. The system of the present invention includes a material basic data storage and processing module; a material balance and heat balance calculation module; a biomass addition amount calculation module; a material basic parameter input module; a metallurgical process parameter input module; a smelting parameter constraint range input module; and a low-carbon smelting parameter output module. The calculation method disclosed by the present invention is based on the material balance and heat balance. On the premise of injecting CO2-containing gas into the blast furnace, the injection amount of the required biomass, as well as the corresponding coke ratio and coal ratio, are obtained through heat difference calculation, realizing low-carbon smelting of the blast furnace. The system and method can guide the injection of CO2-containing gas into the blast furnace and determine the biomass addition amount; the process parameters for meeting the low-carbon smelting of the blast furnace can be obtained at any time according to the types and components of fuels, burden materials, CO2-containing gas, and biomass, and compared with the original smelting conditions, the purpose of reducing the fuel ratio can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace smelting, and relates to an iron-making method and system coupling CO 2 gas with biomass injection. Background Art

[0002] With CO 2 emissions becoming the focus of global attention, steel plants, as major carbon emitters, urgently need a series of new low-carbon smelting technologies to achieve low-carbon production and reduce CO 2 emissions. The energy consumption and carbon emissions in the front-end iron-making system account for more than 70% of the entire steel production process. Energy conservation and emission reduction in blast furnace iron-making are important ways to reduce energy consumption and pollutant emissions in steel plants. Generally, for every 1 t of crude steel produced, approximately 4.2×10 6 kJ of blast furnace gas, 4.1×10 6 kJ of coke oven gas, 1.0×10 4 kJ of converter gas and other waste gases in the plant are generated. The by-product gases in the plant are large in quantity, but the recovery and utilization rate is low. The treatment and utilization efficiency of gases with high CO 2 content, such as blast furnace gas and hot blast stove waste gas, is even lower. Usually, the method of first removing CO 2 and then reusing it is adopted, with a cumbersome process. Moreover, the lower the CO 2 content in the product gas, the higher the treatment cost and the smaller the product gas volume. Therefore, how to achieve the efficient application of CO 2 -containing gas is of great significance for reducing carbon emissions and production costs.

[0003] Under high-temperature conditions, CO 2 will react with C to form CO. Therefore, injecting CO 2 -containing gas into the blast furnace can, on the one hand, provide reducing gas inside the blast furnace, and on the other hand, also achieve the efficient utilization of CO 2 -containing gas and reduce carbon emissions. However, since the reaction between CO 2 and C is an endothermic reaction, the addition of CO 2 will cause insufficient heat in the high-temperature zone of the blast furnace. Therefore, measures need to be taken to thermally compensate the blast furnace to meet the production requirements of the blast furnace. The main measures include adjusting process parameters, such as increasing the oxygen enrichment rate and increasing the coal injection volume; adding thermally compensating substances, such as adding biomass, waste plastics, etc. Adjusting process parameters will increase the fuel ratio of the blast furnace, while biomass in the thermally compensating substances is a green and environmentally friendly energy source, with low S and N content, lower ash content than fossil energy, and less pollutant emissions. Therefore, injecting biomass into the blast furnace can provide thermal compensation for the blast furnace injecting CO 2 -containing gas while reducing the fuel ratio of the blast furnace, further realizing low-carbon smelting in steel plants. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a ironmaking method and system coupling CO 2 gas injection with biomass injection, which comprehensively judges the injection amount of CO 2 gas and the addition amount of heat compensation substances to solve the problem of low-carbon smelting in a blast furnace under the condition of injecting CO 2 gas.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for calculating the addition amount of biomass injected into a blast furnace, comprising the following steps:

[0007] S1 Calculate the material balance and heat balance based on the target raw materials and process parameters to obtain the original coke ratio and coal ratio that satisfy the smooth operation of the blast furnace;

[0008] S2 Calculate the heat income and expenditure according to the addition amount of CO 2 gas, and calculate the initial biomass addition amount a according to the heat supply per unit of biomass 0 ;

[0009] S3 Calculate the material balance and heat balance according to the biomass addition amount. When not satisfied, reduce the biomass addition amount according to the gradient k 1 until the material balance and heat balance are satisfied;

[0010] S4 After S3 is satisfied, judge whether the theoretical combustion temperature and gas utilization rate are within the constraint range. When not satisfied, reduce the original coke ratio and coal ratio according to the gradient k 2 calculate the absolute difference in heat income and expenditure and the corresponding biomass addition amount, and then return to S3, repeat S3 and S4 until the requirements of both steps are satisfied at the same time, and output the smelting parameters.

[0011] Optionally, the judgment basis in step S2 is |relative difference between income and expenditure| = |(income - expenditure) / income * 100%| < 0.50%.

[0012] Optionally, the means of reducing the original coke ratio and coal ratio in step S4 include: reducing the coke ratio completely, reducing the coal ratio completely, and reducing the coke ratio and coal ratio simultaneously in the same proportion.

[0013] An ironmaking method coupling CO 2 gas injection with biomass injection,

[0014] Collect the composition, type and reserve data of CO 2 gas and biomass;

[0015] Calculate the biomass addition amount through the above method and output the smelting parameters;

[0016] Guide the blast furnace to add biomass and inject CO2 Coal gas.

[0017] Optionally, the CO-containing 2 coal gas for blast furnace injection includes decarbonized and denitrified blast furnace gas, coke oven gas, and CO-containing 2 industrial waste gas.

[0018] Optionally, under the conditions of different CO-containing 2 coal gas and biomass types and compositions, the biomass addition amount, coke ratio, and coal ratio corresponding to different injection amounts of CO-containing 2 coal gas are calculated.

[0019] A ironmaking system coupling CO-containing 2 coal gas and biomass injection, including a background analysis system and a front-end usage system;

[0020] The background analysis system includes: a material basic data storage and processing module; a material balance and heat balance calculation module; a biomass addition amount calculation module;

[0021] The front-end usage system includes: a material basic parameter input module; a metallurgical process parameter input module; a smelting parameter constraint interval input module; a low-carbon smelting parameter output module;

[0022] The calculation logic of the biomass addition amount calculation module is based on the method described in any one of claims 1-3.

[0023] Optionally, the material basic data storage and processing module: stores the component, reserve, and performance index data of the CO-containing 2 coal gas, biomass, and other blast furnace materials, and processes missing values and outliers.

[0024] Optionally, the material balance and heat balance calculation module: calculates the top gas composition and gas volume, pig iron composition, tuyere raceway gas volume and composition, in-furnace combustion heat release, reduction heat absorption according to the given raw materials and process parameter conditions, judges whether there is material balance and heat balance, and whether the parameter indexes of gas utilization rate and theoretical combustion temperature meet the constraint conditions.

[0025] Optionally, the material basic parameter input module: the input parameters include: the component, reserve, calorific value, and basic property data of coke, pulverized coal, iron-bearing burden, biomass, and CO-containing 2 coal gas.

[0026] Optionally, the metallurgical process parameter input module: the input parameters include: the blast furnace burden structure, blast furnace smelting element distribution rate, slag basicity, injection medium temperature, CO-containing 2 coal gas injection amount, direct reduction degree, and oxygen enrichment rate parameter values.

[0027] Optionally, the smelting parameter constraint interval input module is used to input the constraint ranges of the theoretical combustion temperature and the gas utilization rate.

[0028] Optionally, the low-carbon smelting parameter output module calculates through the heat difference to output the coke ratio, coal ratio, and the corresponding biomass addition amount that meet low-carbon smelting, so as to guide the blast furnace to inject CO 2 gas.

[0029] The beneficial effects of the present invention are as follows:

[0030] Based on the material balance and heat balance, on the premise that the blast furnace injects CO 2 gas, through theory, this system and method can guide the blast furnace to inject CO 2 gas, determine the addition amount of the heat compensation substance (biomass); the process parameters that meet the low-carbon smelting of the blast furnace can be obtained at any time according to the types and compositions of the original fuel, CO 2 gas, and the heat compensation substance, and compared with the original smelting conditions, the purpose of reducing the fuel ratio is achieved. Calculate the required injection amount of biomass and the values of other important process parameters to realize the low-carbon smelting of the blast furnace.

[0031] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, they will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. Description of the Drawings

[0032] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0033] Figure 1 is the flowchart of the method for calculating the biomass addition amount for blast furnace injection;

[0034] Figure 2 is the flowchart of an ironmaking method coupling CO 2 gas and biomass injection;

[0035] Figure 3 is the schematic diagram of an ironmaking system coupling CO 2 gas and biomass injection. Detailed Embodiments

[0036] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0037] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as limiting the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] Please refer to Figures 1 to 3 , the present invention first discloses a method for calculating the biomass addition amount, including the following steps:

[0040] S1: Calculate the material balance and heat balance according to the original fuel composition, burden structure and production process parameters in the target plant to obtain the original coke ratio and coal ratio of the target blast furnace;

[0041] S2: According to the amount of CO 2 gas addition, keeping the original coke ratio, coal ratio and other process parameters unchanged, calculate the absolute difference Q 差 = heat income - heat expenditure, and then according to the heat supply per unit biomass q, calculate the initial biomass addition amount a 0 = |Q 差 | / q. At this time, the biomass addition amount is a = a 0 ;

[0042] S3: Calculate whether the materials and heat are balanced according to the calculated biomass addition amount a. The judgment criterion is |(income - expenditure) / income * 100%| < 0.50%. When the material balance and heat balance are not satisfied, reduce the biomass addition amount according to a certain gradient k 1 and then perform balance calculations until the material balance and heat balance are satisfied. The gradient k 1 is adjustable (as small as possible). At this time, the biomass addition amount is a i = a 0 - ik 1 (i represents the number of times of reducing the biomass addition amount). When the material balance and heat balance are satisfied, proceed to the next judgment and calculation;

[0043] S4: Judge whether the theoretical combustion temperature and gas utilization rate obtained after calculating the material balance and heat balance with the biomass addition amount a in S3 i are within the constraint range. When the above conditions are met, output relevant smelting parameters. When not within the constraint range, reduce the original coke ratio and coal ratio according to the plant's requirements. The reduction gradient k 2 is adjustable (as small as possible), and other process parameters remain unchanged. Then calculate the absolute difference between heat income and expenditure and the corresponding biomass amount b 1 . At this time, the biomass addition amount is a i+1 = a i + b 1 ; The reduction of the coke ratio and coal ratio according to the plant's requirements includes: reducing the coke completely, reducing the coal completely, and reducing the coke ratio and coal ratio simultaneously in a certain proportion.

[0044] S5: According to the calculated biomass addition amount a i+1 Repeat steps S3 and S4 until the adjusted coke ratio, coal ratio, and biomass addition amount calculation satisfy the material balance, heat balance, and the theoretical combustion temperature and gas utilization rate are within the constraint range, and output the corresponding smelting parameters.

[0045] The present invention also provides a CO-containing 2 ironmaking method coupling CO-containing gas and biomass injection. Collect data such as the composition, type, and reserve of CO-containing 2 gas (decarbonized and denitrified blast furnace gas, coke oven gas, industrial waste gas containing CO 2 ), and biomass, and process the data for missing values and outliers; calculate the material balance and heat balance based on the original fuels and process parameters of the target blast furnace to obtain the original coke ratio and coal ratio that satisfy the smooth operation of the blast furnace; select available basic data of CO-containing 2 gas and biomass, and input the CO-containing 2The injection volume of gas and the constraint intervals of related parameters are maintained while keeping the other process parameters of the target blast furnace unchanged. With the goal of meeting the constraint intervals of gas utilization rate and theoretical combustion temperature, the coke ratio and coal ratio are reduced according to requirements, and the addition amount of biomass is calculated through heat difference calculation.

[0046] The blast furnace injects CO 2 gas, including decarbonized and denitrified blast furnace gas, coke oven gas and CO 2 industrial waste gas, reducing the CO 2 concentration requirement of the process flow for removing CO 2 At the same time, heat compensation is carried out by adding biomass, which also reduces the carbon emissions of the steel plant. Based on material balance and heat balance, a calculation model for biomass addition amount is constructed according to the constraint intervals of smelting parameters. Under different conditions of CO 2 gas and biomass types and compositions, the biomass addition amount, coke ratio and coal ratio corresponding to different injection volumes of CO 2 gas are measured, and the injection volume and some process parameter values are dynamically adjusted to achieve the purpose of low-carbon smelting.

[0047] The present invention also provides an ironmaking system for coupling CO 2 gas and biomass injection based on the above measurement method, including a background analysis system and a front-end use system. The background analysis system includes: a material basic data storage and processing module; a material balance and heat balance measurement module; a biomass addition amount calculation module. The front-end use system includes: a material basic parameter input module; a metallurgical process parameter input module; a smelting parameter constraint interval input module; a low-carbon smelting parameter output module.

[0048] The function of the material basic data storage and processing module is to store and process the missing value and outlier of the index data such as the composition, reserve and performance of the collected CO 2 gas (decarbonized and denitrified blast furnace gas, coke oven gas, CO 2 industrial waste gas), biomass and other blast furnace materials. Among them, the CO 2 content range is 1% - 10%. The material balance and heat balance measurement module calculates the top gas composition and gas volume, pig iron composition, gas volume and composition in the tuyere raceway, heat release during combustion in the furnace, and reduction heat absorption according to the given raw materials and process parameter conditions, and judges whether the material balance and heat balance are achieved, and whether the parameter indicators such as gas utilization rate and theoretical combustion temperature meet the actual requirements; the parameters input by the material basic parameter input module include: input coke, pulverized coal, iron-bearing burden, biomass, CO 2Composition, reserves, calorific value and basic characteristic data of the gas; the parameters input by the metallurgical process parameter input module include: input of the target blast furnace burden structure, distribution rate of smelting elements in the blast furnace, slag basicity, temperature of the injection medium, and CO content 2 Parameter values of the gas injection volume, direct reduction degree, and oxygen enrichment rate; the parameters input by the smelting parameter constraint interval input module include: input of the constraint range values of the theoretical combustion temperature and gas utilization rate that meet the blast furnace smelting based on actual production and theoretical calculation experience; the low-carbon smelting parameter output module calculates through the heat difference and outputs the coke ratio, coal ratio, and corresponding biomass addition amount that meet low-carbon smelting to guide the blast furnace to inject CO-containing 2 gas.

[0049] Example 1

[0050] Step 1: Obtain the material situation of a 3200m 3 blast furnace in a steel plant. The steel plant currently uses coke A, pulverized coal B, mixed ore, and mixed solvent. In addition, it has decarbonized and denitrified blast furnace gas (containing 2% CO 2 ), and biomass A.

[0051] Step 2: Calculate the initial coke ratio and coal ratio of the target blast furnace, calculate the material balance and heat balance based on the original fuel and process parameters of the target blast furnace. The original process parameters mainly include: distribution rate of elements entering pig iron: η Fe = 99.75%, η Mn = 60.05%; slag basicity R is 1.25; direct reduction degree of iron r d is 0.5; top gas temperature is 159°C, oxygen enrichment rate is 0.01, etc. Under the condition of not injecting CO-containing 2 gas, obtain the original coke ratio C 焦0 and coal ratio C 煤0 , which are 355 kg / t and 160 kg / t respectively.

[0052] Step 3: Determine the injection volume V 2 of CO-containing 气 gas, the reduction gradient value k 1 of biomass addition amount, the reduction gradient value k 2 of coke ratio and coal ratio, and the range values of parameters such as gas utilization rate and theoretical combustion temperature. According to the historical production data and theoretical calculation of the blast furnace in this steel plant, obtain the range values of important process parameters: 0.48 ≤ gas utilization rate ≤ 0.49; 2100°C ≤ theoretical combustion temperature ≤ 2250°C. According to the plant's requirements and reserve situation, the injection volume of CO-containing 2 gas is 40 m 3 / t, the reduction gradient value k 1 of biomass addition amount is 0.05 kg / t, and the reduction gradient values of coke ratio and coal ratio are 1 kg / t.

[0053] Step 4, Blast furnace CO 2 Calculation of the required heat compensation biomass injection volume corresponding to the CO gas injection volume

[0054] S1: CO-containing 2 The added amount of gas is 40 m 3 / t. Keeping the original coke ratio, coal ratio and other process parameters unchanged, the absolute difference in heat income and expenditure is calculated to be -0.03 GJ / t, and the heat supply per unit biomass is 0.025 GJ / kg. Calculate the initial biomass addition amount a 0 = 0.03 / 0.025 = 1.20 kg / t. At this time, the biomass addition amount is a = a 0 = 1.20 kg / t;

[0055] S2: Based on the calculated biomass addition amount of 1.20 kg / t, with the coke ratio and coal ratio being 355 kg / t and 160 kg / t respectively, calculate the material and heat income and expenditure, and judge that the material balance and heat balance are satisfied, and proceed to the next judgment and calculation;

[0056] S3: According to S2, the calculated theoretical combustion temperature and gas utilization rate are 2192 °C and 0.468 respectively. Since the gas utilization rate does not meet the constraint interval, it is reduced according to the ratio of coke ratio to coal ratio of 1:1, and the reduction gradient k 2 is 1 kg / t. After reduction, they are 354 kg / t and 159 kg / t respectively, and other process parameters remain unchanged. Then calculate the absolute difference in heat income and expenditure to be -0.005 GJ / t and the corresponding biomass amount b 1 is 0.20 kg / t. At this time, the biomass addition amount is a 1 = a 0 + b 1 = 1.20 + 0.20 = 1.40 kg / t;

[0057] S4: According to the calculated biomass addition amount a 1 Repeat steps S2 - S3. When repeating for the 8th time, the coke ratio and coal ratio are 347 kg / t and 152 kg / t respectively, and the biomass addition amount is 5 kg / t. Calculate that the material balance and heat balance are satisfied, and the theoretical combustion temperature and gas utilization rate are 2186 °C and 0.481 respectively, within the constraint interval.

[0058] Step 5, Output the coke ratio of 347 kg / t, the coal ratio of 152 kg / t, the biomass addition amount of 5 kg / t, and the fuel ratio is reduced by 16 kg / t. The calculation is completed.

[0059] Example 2

[0060] Step 1, Obtain a certain iron and steel plant with 3200 m 3Material situation of a blast furnace at a certain iron and steel plant. Currently, coke A, pulverized coal B, mixed ore, and mixed solvent are used. In addition, there is blast furnace gas with decarbonization and denitrification (containing 5% CO 2 ), and biomass A.

[0061] Step 2: Calculate the initial coke ratio and coal ratio of the target blast furnace. Calculate the material balance and heat balance based on the original fuels and process parameters of the target blast furnace. The original process parameters mainly include: the distribution rate of elements entering pig iron: η Fe = 99.75%, η Mn = 60.05%; the slag basicity R is 1.25; the direct reduction rate of iron r d is 0.5; the top gas temperature is 159°C, the oxygen enrichment rate is 0.01, etc. Under the condition of not injecting CO 2 -containing gas, the original coke ratio C 焦0 and coal ratio C 煤0 that meet the smooth operation of the blast furnace are obtained, which are 355 kg / t and 160 kg / t respectively.

[0062] Step 3: Determine the injection volume V 2 of CO 气 -containing gas, the reduction gradient value k 1 of biomass addition, the reduction gradient values k 2 of coke ratio and coal ratio, the heat supply per unit biomass, the gas utilization rate, and the range values of parameters such as the theoretical combustion temperature. According to the historical production data of the blast furnace of this iron and steel plant collected and theoretical calculations, the range values of important process parameters are obtained: 0.48 ≤ gas utilization rate ≤ 0.49; 2100°C ≤ theoretical combustion temperature ≤ 2250°C. According to the plant's requirements and reserve situation, the injection volume of CO 2 -containing gas is 60 m 3 / t, the reduction gradient value k 1 of biomass addition is 0.1 kg / t, the heat supply per unit biomass q is 0.025 GJ / kg, and the reduction gradient values of coke ratio and coal ratio are 2 kg / t, only reducing the coal.

[0063] Step 4: Calculation of the heat compensation biomass injection volume corresponding to the injection volume of CO 2 -containing gas in the blast furnace

[0064] S1: When the addition amount of CO 2 -containing gas is 60 m 3 / t, keeping the original coke ratio, coal ratio, and other process parameters unchanged, the absolute difference Q 差 in heat income and expenditure is calculated to be -0.075 GJ / t. Calculate the initial biomass addition amount a 0 = 0.075 / 0.025 = 3.00 kg / t. At this time, the biomass addition amount is a = a 0 = 3.00 kg / t;

[0065] S2: Calculate the material and heat income and expenditure based on the calculated biomass addition of 3.00 kg / t, coke ratio and coal ratio of 355 kg / t and 160 kg / t respectively. It is judged that the heat balance is not satisfied. Reduce the biomass addition to 2.90 kg / t and then calculate the material and heat income and expenditure. Repeat the above operations until the biomass addition is reduced to 2.60 kg / t and the material balance and heat balance are satisfied, and then proceed to the next judgment and calculation;

[0066] S3: According to the theoretical combustion temperature and gas utilization rate calculated to be 2140 °C and 0.456 respectively when the biomass addition in S2 is 2.60 kg / t, and since the gas utilization rate does not meet the constraint interval, in the way of only reducing coal, reduce the coal ratio to 158 kg / t, keep other process parameters unchanged, and then calculate the absolute difference Q of the heat income and expenditure 差 is 0.002 GJ / t, then no more biomass needs to be added, that is, b 1 is 0 kg / t, and the biomass addition at this time is a 1 = a 0 + b 1 = 2.60 + 0 = 2.60 kg / t;

[0067] S4: According to the calculated biomass addition a 1 Repeat steps S2 - S3. When repeating for the 16th time, the coke ratio and coal ratio are 355 kg / t and 128 kg / t respectively, and the biomass addition is 9.52 kg / t. It is calculated that the material balance and heat balance are satisfied, and the theoretical combustion temperature and gas utilization rate are 2150 °C and 0.482 respectively, which are within the constraint interval.

[0068] Step 5, output the coke ratio of 355 kg / t, coal ratio of 128 kg / t, biomass addition of 9.52 kg / t, the fuel ratio is reduced by 32 kg / t, and the calculation ends.

[0069] Example 3

[0070] Step 1, obtain the material situation of a 3200 m 3 blast furnace in a certain iron and steel plant. A certain iron and steel plant currently uses coke A, pulverized coal B, mixed ore and mixed solvent. In addition, it has decarbonized and denitrified blast furnace gas (containing 7% CO 2 ), biomass A.

[0071] Step 2, calculate the initial coke ratio and coal ratio of the target blast furnace, and calculate the material balance and heat balance based on the original fuel and process parameters of the target blast furnace. The original process parameters mainly include: the distribution rate of elements entering pig iron: η Fe = 99.75%, η Mn = 60.05%; the slag basicity R is 1.25; the direct reduction rate of iron r dis 0.5; the top gas temperature is 159 °C, the oxygen enrichment rate is 0.01, etc. Under the condition of not injecting CO-containing 2 gas, the original coke ratio C 焦0 and coal ratio C 煤0 are obtained to meet the smooth operation of the blast furnace, which are 355 kg / t and 160 kg / t respectively.

[0072] Step 3, determine the injection volume V 2 of CO-containing 气 gas, the reduction gradient value k 1 of biomass addition, the reduction gradient values k 2 of coke ratio and coal ratio, the heat supply per unit biomass, the gas utilization rate, the theoretical combustion temperature and other parameter range values. According to the historical production data of the blast furnace of this steel plant collected and theoretical calculations, the range values of important process parameters are obtained: 0.47 ≤ gas utilization rate ≤ 0.49; 2100 °C ≤ theoretical combustion temperature ≤ 2250 °C. According to the plant's demand and reserve situation, the injection volume of CO-containing 2 gas is 60 m 3 / t, the reduction gradient value k 1 of biomass addition is 0.1 kg / t, the heat supply per unit biomass q is 0.025 GJ / kg, and the reduction gradient values of coke ratio and coal ratio are 2 kg / t, only reducing coke.

[0073] Step 4, calculation of the heat compensation biomass injection volume corresponding to the CO-containing 2 gas injection volume in the blast furnace

[0074] S1: When the addition volume of CO-containing 2 gas is 60 m 3 / t, keeping the original coke ratio, coal ratio and other process parameters unchanged, the absolute difference Q 差 of heat income and expenditure is calculated to be -0.094 GJ / t, and the initial biomass addition amount a 0 = 0.094 / 0.025 = 3.73 kg / t. At this time, the biomass addition amount is a = a 0 = 3.73 kg / t;

[0075] S2: From the calculated biomass addition amount of 3.73 kg / t, with the coke ratio and coal ratio being 355 kg / t and 160 kg / t respectively, calculate the material and heat income and expenditure, and judge that the heat balance is not satisfied. Reduce the biomass addition amount to 3.63 kg / t and then calculate the material and heat income and expenditure. Repeat the above operations until the biomass addition amount is reduced to 3.13 kg / t, when the material balance and heat balance are satisfied, and proceed to the next judgment and calculation;

[0076] S3: Based on the theoretical combustion temperature and gas utilization rate calculated when the biomass addition amount in S2 is 3.13 kg / t, which are 2132 °C and 0.455 respectively, and the gas utilization rate does not meet the constraint interval. In the way of only reducing coke ratio, the coke ratio is reduced to 353 kg / t, and other process parameters remain unchanged. Then calculate the absolute difference Q of heat income and expenditure 差 is -0.0018 GJ / t, then the biomass addition amount b 1 is 0.07 kg / t, and the biomass addition amount at this time is a 1 = a 0 + b 1 = 3.13 + 0.07 = 3.20 kg / t;

[0077] S4: According to the calculated biomass addition amount a 1 Repeat steps S2 - S3. When repeating for the 13th time, the coke ratio and coal ratio are 329 kg / t and 160 kg / t respectively, the biomass addition amount is 10.10 kg / t. It is calculated that the material balance and heat balance are satisfied, and the theoretical combustion temperature and gas utilization rate are 2100 °C and 0.474 respectively, which are within the constraint interval.

[0078] Step 5, output the coke ratio of 329 kg / t, the coal ratio of 160 kg / t, the biomass addition amount of 10.10 kg / t, the fuel ratio is reduced by 26 kg / t, and the calculation ends.

[0079] Note: The biomass addition amount can be limited by the reserve. When the biomass addition amount exceeds the limit value during the calculation process, it can be adjusted by reducing the CO 2 gas injection amount or adjusting parameters such as direct reduction degree, and the calculation method remains unchanged. In addition, through multiple calculations under the same conditions, the biomass addition amount scheme with the lowest fuel ratio can be obtained.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for calculating the addition amount of biomass in blast furnace injection, characterized in that, it includes the following steps: S1 Calculate the material balance and heat balance based on the target raw materials and process parameters to obtain the original coke ratio and coal ratio that satisfy the smooth operation of the blast furnace; S2 Calculate the heat balance based on the CO 2 content in the coal gas, and calculate the initial biomass addition amount a according to the heat supply per unit of biomass 0 ; S3 calculates the material balance and heat balance based on the biomass addition amount. If not satisfied, it is adjusted according to the gradient k 1 Reduce the biomass addition amount until the material balance and heat balance are satisfied. The judgment criterion is |(income - expenditure) / income × 100%| < 0.50%; After S4 satisfies S3, it is judged whether the theoretical combustion temperature and the gas utilization rate are within the constraint interval. If not, according to the gradient k 2 Reduce the original coke ratio and coal ratio. The means of reducing the original coke ratio and coal ratio include: reducing the coke ratio completely, reducing the coal ratio completely, and reducing the coke ratio and coal ratio simultaneously in the same proportion. Calculate the absolute difference in heat income and expenditure and the corresponding biomass addition amount, and then return to S3. Repeat S3 and S4 until the requirements of both steps are satisfied simultaneously, and output the smelting parameters.

2. A kind of ironmaking method coupling coal gas with biomass injection containing CO 2 The ironmaking method coupling coal gas with biomass injection characterized in that: Collect CO-containing 2 Composition, type and reserve data of coal gas and biomass, including CO 2 The coal gas is decarbonized and denitrified blast furnace gas or coke oven gas; Calculate the addition amount of biomass according to the method described in claim 1 and output the smelting parameters; Guide the blast furnace to add biomass and inject CO-containing gas according to smelting parameters 2 Among them, under the conditions of different CO-containing gases 2 and types and compositions of biomass, calculate the biomass addition amounts, coke ratios, and coal ratios corresponding to different injection amounts of CO-containing gas 2 ​ 3. A kind of ironmaking system coupling coal gas with biomass injection containing CO 2 which couples the blast furnace gas with the biomass injection characterized in that: It includes a background analysis system and a front-end use system; The background analysis system includes: a material basic data storage and processing module for storing the component, reserve, and performance index data of the CO-containing 2 blast furnace gas, biomass, and other blast furnace materials, and processing missing values and outliers; a material balance and heat balance calculation module for calculating the top gas composition and gas volume, pig iron composition, gas volume and composition in the tuyere raceway, heat release during combustion in the furnace, and reduction heat absorption according to the raw materials and process parameter conditions, and determining whether the material balance and heat balance are satisfied; a biomass addition amount calculation module whose calculation logic is based on the method described in claim 1; The described front-end usage system includes: a material basic parameter input module for inputting the composition, reserves, calorific value, and basic characteristic data of coke, pulverized coal, iron-bearing burden, biomass, and CO 2 gas; a metallurgical process parameter input module for inputting the blast furnace burden structure, blast furnace smelting element distribution rate, slag basicity, injection medium temperature, CO 2 gas injection volume, direct reduction degree, and parameter values of the oxygen enrichment rate; a smelting parameter constraint interval input module for inputting the constraint ranges of the theoretical combustion temperature and gas utilization rate; a low-carbon smelting parameter output module for calculating and outputting the coke ratio, coal ratio, and corresponding biomass addition amount that meet low-carbon smelting through heat difference calculation.

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