Method for determining optimal amount of injected hydrogen-rich gas based on energy mass model of hydrogen-rich blast furnace

Abstract

The invention relates to a method for determining the optimal amount of injected hydrogen-rich gas based on a hydrogen-rich blast furnace energy mass model. The method comprises the following steps: constructing a hydrogen-rich blast furnace energy mass balance model; inputting initial conditions of the constructed energy and mass balance model of the hydrogen-rich blast furnace; adjusting an iterative hydrogen utilization rate and a theoretical combustion temperature parameter; on the basis of the material balance relative error and the heat loss constraint condition, the constraint condition in the subsequent prediction process is stipulated; the consumption of the solid fuel is reduced while the injection amount of the hydrogen-rich gas is increased; the solid fuel ratio and the carbon emission under each injection system are obtained; and the optimal hydrogen-rich gas spraying amount of the hydrogen-rich blast furnace is determined. According to the method, the hydrogen-rich effects of a small amount of hydrogen-rich gas and a large amount of hydrogen-rich gas are fully considered, the influence on the solid fuel ratio, carbon emission and other parameters after the hydrogen-rich gas is injected is scientifically evaluated, and then the optimal selection of the injection amount of the hydrogen-rich gas is achieved, so that the hydrogen-rich injection effect is guaranteed, the fuel utilization rate is increased, and energy is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace ironmaking, and in particular to a method for determining an optimal amount of injected hydrogen-rich gas based on an energy quality model of a hydrogen-rich blast furnace. Background Art

[0002] The steel industry is an important pillar industry in the national economy, and it is also a major energy consumer and carbon emitter. Among them, the blast furnace ironmaking process is second to none in terms of energy consumption and carbon emissions, and is the main potential concentrated process for energy conservation and consumption reduction in the future. Blast furnace hydrogen-rich injection technology is an important green and low-carbon technology for modern blast furnaces, and is also the central link in the optimization of the ironmaking system structure. This technology can not only adjust the blast furnace thermal system, but more importantly, it can replace coke to play the role of heat supply and reducing agent, effectively reduce the amount of coke, reduce smelting energy consumption and carbon emissions, and reduce pig iron costs, which is in line with the green and low-carbon development of the steel industry.

[0003] In order to develop hydrogen-rich injection technology, achieve energy conservation and emission reduction, increase production and generate income, many ironmaking workers have been studying how to increase the amount of hydrogen-rich gas injection, but they have confused the difference between the limit amount of hydrogen-rich gas injection and the optimal amount of hydrogen-rich gas injection. On the one hand, after the amount of hydrogen-rich gas injection is increased, the indirect reduction degree in the furnace increases, and part of the coke used for direct reduction consumption and heating can be replaced, so that the solid fuel ratio and carbon emissions are reduced; on the other hand, with the increase in the amount of hydrogen-rich gas injection, the hydrogen utilization rate decreases, the increase in the indirect reduction degree slows down, and at the same time, the top gas temperature increases, which causes more heat energy waste without circulating the top gas, and the solid fuel ratio and carbon emissions decrease slowly. Continuing to increase the amount of hydrogen-rich gas injection has poor results.

[0004] Therefore, how to determine the most appropriate amount of hydrogen-rich gas to be sprayed into a hydrogen-rich blast furnace so as to achieve the best energy-saving and emission-reduction effect will become an urgent problem to be solved. Summary of the invention

[0005] In response to the above problems, the purpose of the present invention is to provide a method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace, which can overcome the problem of unknown specific optimal hydrogen-rich amount of the hydrogen-rich blast furnace and achieve the optimal selection of the hydrogen-rich gas injection amount, thereby ensuring the hydrogen-rich injection effect and improving fuel utilization.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for determining the optimal amount of hydrogen-rich gas to be injected based on an energy quality model of a hydrogen-rich blast furnace proposed in the present invention comprises the following steps:

[0008] S1. According to the material flow and energy flow properties inside the blast furnace, an energy-mass balance model of a hydrogen-rich blast furnace is constructed, which includes material balance calculation, heat balance calculation, and theoretical combustion temperature calculation model;

[0009] S2. Enter the initial conditions of the hydrogen-rich blast furnace energy and mass balance model constructed in step S1;

[0010] S3, adjusting the iterative hydrogen utilization rate and theoretical combustion temperature parameters according to the initial conditions in step S2;

[0011] S4, based on the material balance relative error and heat loss constraint conditions obtained by theoretical calculation in step S3, specify the constraint conditions in the subsequent prediction process;

[0012] S5. According to the constraint conditions obtained in step S4, the amount of hydrogen-rich gas injection is increased while the amount of solid fuel is reduced;

[0013] S6. Based on the calculation result of step S5, obtain the solid fuel ratio and carbon emission under each injection system;

[0014] S7. Based on the solid fuel ratio and carbon emission under each injection system obtained in step S6, determine the optimal amount of hydrogen-rich gas injected into the hydrogen-rich blast furnace.

[0015] Furthermore, in step S1, the energy and mass balance model of the hydrogen-rich blast furnace adds a hydrogen-rich gas input terminal in the material balance part, the heat balance adopts the first total heat balance, and the theoretical combustion temperature model additionally adds the heat release term of methane combustion in the hydrogen-rich gas.

[0016] Furthermore, in step S2, the initial conditions include raw fuel data, blast parameters, preset molten iron composition, mixed ore ratio, and oxygen enrichment rate original parameters.

[0017] Furthermore, the step S3 specifically includes: first assuming a hydrogen utilization rate to obtain the relative proportion of H2 and H2O in the specific furnace top gas, and then calculating the theoretical hydrogen utilization rate after obtaining the complete furnace top gas composition, and repeatedly iterating the preset value of the hydrogen utilization rate so that the two hydrogen utilization rates are equal; the theoretical combustion temperature calculation requires a preset temperature, and then the theoretical combustion temperature is calculated based on the temperature, and the preset temperature is continuously iterated so that the two temperatures are equal. The preset temperature at this time is the theoretical combustion temperature.

[0018] Furthermore, the calculation formula for hydrogen utilization rate and theoretical combustion temperature is as follows:

[0019]

[0020]

[0021] Where: is the hydrogen utilization rate; η CO is the carbon monoxide utilization rate; T f is the theoretical combustion temperature, °C; is the heat released by the combustion of coke at the tuyere, kJ / tHM; Q fuel is the heat released by the combustion of the injected fuel, kJ / tHM; Q Coke is the sensible heat brought in by coke, kJ / tHM; Q H Sensible heat brought in by hydrogen-rich gas, kJ / tHM; Q W The heat consumed by the reaction between fuel and water in the blast, kJ / tHM; Q Coke-decom is the heat of decomposition and volatilization of pulverized coal, kJ / tHM; is the heat released by the combustion of methane in hydrogen-rich gas, kJ / tHM; Q r-slag is the slag forming heat, kJ / tHM; is the average heat capacity of gas in the tuyere vortex zone, kJ / (℃·m 3 ); is the gas volume in the tuyere vortex zone, m 3 / tHM;C a_i is the average heat capacity of the ash content of fuel i, i is coke or coal powder, kJ / (℃·kg); m a_i is the ash content of fuel i, kg / tHM; C w is the average heat capacity of unburned coal powder, kJ / (℃·kg); m w is the amount of unburned coal powder, kJ / tHM.

[0022] Furthermore, in step S4, the relative error of material balance is controlled within 0.1%; the heat loss is guaranteed to be within 4×10 5 kJ / tHM or above.

[0023] Furthermore, the step S5 specifically includes: increasing the injection amount of the hydrogen-rich gas in a stepwise manner, while reducing the amount of solid fuel, and limiting the reduction range of the amount of solid fuel with heat loss as a constraint condition.

[0024] Furthermore, in step S6, carbon emissions only consider direct carbon emissions, including two algorithms: only calculating blast furnace top CO2 emissions and converting CO into carbon emissions; the relevant calculation formula is as follows:

[0025]

[0026]

[0027] Where: To calculate only the carbon emissions from the blast furnace top CO2 emissions, m 3 / tHM; is the volume of CO2 in the hydrogen-rich blast furnace top gas, m 3 / tHM; is the carbon emission after conversion to CO, m 3 / tHM; 0.719 is the ratio of the calorific value of CO and C; is the volume of CO in the hydrogen-rich blast furnace top gas, m 3 / tHM.

[0028] Furthermore, the step S7 specifically includes: after obtaining the solid fuel consumption and carbon emission data through theoretical calculation, jointly establishing the gradient evaluation parameter E C It is used to evaluate the necessity of continuing to inject additional hydrogen-rich gas, and in the process of increasing the amount of hydrogen-rich gas injection, the last one makes E C The injection amount that meets the conditions is the optimal injection amount of hydrogen-rich gas.

[0029] Furthermore, E C The parameter calculation method is:

[0030] E C =C1+C2+C3

[0031] Where: when the reduction in solid fuel consumption is less than 75% of the maximum reduction, C1 takes 0, otherwise it takes 1; when the reduction in the first type of carbon emissions decreases, C2 takes 0, otherwise it takes 1; when the reduction in the second type of carbon emissions is less than 60% of the maximum reduction, C3 takes 0, otherwise it takes 1;

[0032] If the gradient evaluation parameter E C ≥2, the hydrogen-rich gas injection rate HGI i It is more appropriate to continue to increase the injection rate of hydrogen-rich gas. If the next gradient injection rate makes E C <2, then the gradient HGI i For the optimal amount of hydrogen-rich gas to be sprayed.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention fully considers the hydrogen-enriching effects of a small amount of hydrogen-enriching and a large amount of hydrogen-enriching, and scientifically evaluates the influence of the injection of hydrogen-enriched gas on parameters such as solid fuel ratio and carbon emission, thereby achieving the optimal selection of the injection amount of hydrogen-enriched gas, thereby ensuring the effect of hydrogen-enriched injection, improving fuel utilization, saving energy, and achieving revenue generation. The simulation calculation of the present invention is highly practical and widely applicable, and the obtained evaluation parameters can be applied to the current status of blast furnaces in various ironmaking plants, which is of great significance for determining and optimizing the injection system during hydrogen-enriched injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic flow chart of a method for determining the optimum amount of hydrogen-rich gas to be injected based on an energy quality model of a hydrogen-rich blast furnace proposed by the present invention;

[0036] Figure 2 It is a schematic diagram of the change of solid fuel ratio under different injection conditions;

[0037] Figure 3 Schematic diagram of carbon emission (without CO conversion) changes under different injection conditions;

[0038] Figure 4 Schematic diagram of the changes in carbon emissions (converted into CO) under different injection conditions. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] See attached Figure 1 The present invention proposes a method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace, which specifically includes the following steps:

[0041] S1. According to the material flow and energy flow properties inside the blast furnace, a hydrogen-rich blast furnace energy and mass balance model is constructed, which includes material balance calculation, heat balance calculation and theoretical combustion temperature calculation model. Compared with the ordinary blast furnace energy and mass balance model, the material balance part adds a hydrogen-rich gas input terminal, the heat balance adopts the first total heat balance, and the theoretical combustion temperature model adds an additional methane combustion exothermic term in the hydrogen-rich gas.

[0042] S2. Enter the initial conditions such as raw fuel data, blast parameters, preset molten iron composition, mixed ore ratio, oxygen enrichment rate, etc. of the energy and mass balance model of the hydrogen-rich blast furnace in step S1; the above original parameters are all provided on-site by the ironmaking plant.

[0043] S3, according to the initial conditions described in step S2, adjusting the key parameters such as iterative hydrogen utilization rate and theoretical combustion temperature; specifically including:

[0044] It is necessary to first assume a hydrogen utilization rate to obtain the relative proportion of H2 and H2O in the specific furnace top gas. After obtaining the complete furnace top gas composition, the theoretical hydrogen utilization rate is calculated, and the preset value of the hydrogen utilization rate is repeatedly iterated to make the two hydrogen utilization rates equal. The theoretical combustion temperature calculation is similar to the hydrogen utilization rate. It is also necessary to preset a temperature, and then calculate the theoretical combustion temperature based on this temperature. The preset temperature is continuously iterated to make the two temperatures equal. The preset temperature at this time is the theoretical combustion temperature.

[0045] Furthermore, the calculation formula for hydrogen utilization rate and theoretical combustion temperature is as follows:

[0046]

[0047]

[0048] Where: is the hydrogen utilization rate; η CO is the carbon monoxide utilization rate; T f is the theoretical combustion temperature, °C; is the heat released by the combustion of coke at the tuyere, kJ / tHM; Q fuel is the heat released by the combustion of the injected fuel, kJ / tHM; Q Coke is the sensible heat brought in by coke, kJ / tHM; Q H Sensible heat brought in by hydrogen-rich gas, kJ / tHM; Q W The heat consumed by the reaction between fuel and water in the blast, kJ / tHM; Q Coke-decom is the heat of decomposition and volatilization of pulverized coal, kJ / tHM; is the heat released by the combustion of methane in hydrogen-rich gas, kJ / tHM; Q r-slag is the slag forming heat, kJ / tHM; is the average heat capacity of gas in the tuyere vortex zone, kJ / (℃·m 3 ); is the gas volume in the tuyere vortex zone, m 3 / tHM;C a_i is the average heat capacity of the ash content of fuel i, i is coke or coal powder, kJ / (℃·kg); m a_i is the ash content of fuel i, kg / tHM; C w is the average heat capacity of unburned coal powder, kJ / (℃·kg); m w is the amount of unburned coal powder, kJ / tHM.

[0049] S4. Based on the constraints such as the relative error of material balance and heat loss obtained by theoretical calculation in step S3, the constraints in the subsequent prediction process are specified; to ensure the accuracy of theoretical calculation, the relative error of material balance should be controlled within 0.1%; to ensure the normal operation of blast furnace, the heat loss should be guaranteed within 4×10 5 kJ / tHM or above.

[0050] S5. According to the constraint conditions obtained in step S4, the amount of hydrogen-rich gas injection is increased while the amount of solid fuel is reduced;

[0051] When increasing the injection amount of hydrogen-rich gas, it is necessary to increase the injection amount of hydrogen-rich gas in a step-by-step manner, while reducing the amount of solid fuel, and limit the reduction range of the amount of solid fuel with heat loss as the constraint condition;

[0052] During the above adjustment process, while increasing the injection volume of hydrogen-rich gas, it is necessary not only to continuously adjust the preset hydrogen utilization rate and theoretical combustion temperature, but also to change the ore proportion (the ratio of sintered ore and pelletized ore) to maintain the stability of the slag alkalinity.

[0053] S6. Based on the calculation results of step S5, the solid fuel ratio and carbon emissions under each injection system are obtained; wherein, the carbon emissions only consider direct carbon emissions, including two algorithms: only calculating the CO2 emissions from the blast furnace top and converting CO into carbon emissions; the relevant calculation formula is as follows:

[0054]

[0055]

[0056] Where: To calculate only the carbon emissions from the blast furnace top CO2 emissions, m 3 / tHM; is the volume of CO2 in the hydrogen-rich blast furnace top gas, m 3 / tHM; is the carbon emission after conversion to CO, m 3 / tHM; 0.719 is the ratio of the calorific value of CO and C; is the volume of CO in the hydrogen-rich blast furnace top gas, m 3 / tHM.

[0057] S7, based on the solid fuel ratio and carbon emission under each injection system obtained in step S6, determining the optimal amount of hydrogen-rich gas injected into the hydrogen-rich blast furnace; specifically comprising:

[0058] After theoretical calculations to obtain data such as solid fuel consumption and carbon emissions, the gradient evaluation parameter E is jointly established. C It is used to evaluate the necessity of continuing to inject additional hydrogen-rich gas, and in the process of increasing the amount of hydrogen-rich gas injection, the last one makes E C The injection amount that meets the conditions is the optimal injection amount of hydrogen-rich gas.

[0059] Established E C The parameter calculation method is:

[0060] E C =C1+C2+C3

[0061] Wherein: when the reduction in solid fuel consumption is less than 75% of the maximum reduction, C1 takes 0, otherwise it takes 1; when the reduction in the first type of carbon emissions decreases, C2 takes 0, otherwise it takes 1; when the reduction in the second type of carbon emissions is less than 60% of the maximum reduction, C3 takes 0, otherwise it takes 1.

[0062] If the gradient evaluation parameter E C ≥2, the hydrogen-rich gas injection rate HGI i It is more appropriate, and we can try to continue to increase the injection rate of hydrogen-rich gas. If the next gradient injection rate makes E C <2, then the gradient HGI i That is the optimum amount of hydrogen-rich gas to be injected.

[0063] The principles and features of the present invention are described below in conjunction with specific examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0064] The energy-quality balance model of hydrogen-rich blast furnace was established, and the original data of the ironmaking plant was entered into the theoretical model. The relevant data are shown in Tables 1 to 4:

[0065] Table 1 Raw material composition

[0066]

[0067] Table 2 Fuel composition

[0068]

[0069] Table 3 Preset molten iron composition

[0070]

[0071] Table 4 Blast furnace injection parameters

[0072]

[0073] Since hydrogen-rich injection will significantly increase the amount of coal gas in the furnace, it has a great impact on the theoretical combustion temperature. In order to maintain sufficient heat in the lower part of the blast furnace, the lower limit of the theoretical combustion temperature is set at 2000℃. The last level of hydrogen-rich gas injection in the following hydrogen-rich scheme is the hydrogen-rich gas injection amount below the lower limit of the theoretical combustion temperature. The optimal hydrogen-rich gas amount should be selected within the range of 0 to this value.

[0074] Table 5 Blast furnace hydrogen-rich injection scheme

[0075]

[0076] Note: The composition of coke oven gas is 60% H2, 30% CH4, 5% CO, and 5% N2.

[0077] After the model adjustment and iterative calculation, the parameters such as solid fuel ratio and carbon emission are obtained, such as Figure 2 to Figure 4 shown.

[0078] The initial solid fuel ratio is 542kg / t (coke 418kg / t, coal powder 124kg / t), and the initial carbon emission is 330.56m 3 / t or 629.36m 3 / t (after conversion to CO).

[0079] ① Solid fuel ratio

[0080] The solid fuel ratio under coke oven gas 1# operating condition was 531.2kg / t, a decrease of 1.99%; the solid fuel ratio under coke oven gas 2# operating condition was 521.7kg / t, a decrease of 3.75%, an increase of 1.76%; the solid fuel ratio under coke oven gas 3# operating condition was 513.5kg / t, a decrease of 5.26%, an increase of 1.51%; the solid fuel ratio under coke oven gas 4# operating condition was 505.4kg / t, a decrease of 6.75%, an increase of 1.49%; the solid fuel ratio under coke oven gas 5# operating condition was 499kg / t, a decrease of 7.93%, an increase of 1.18%.

[0081] The solid fuel ratio under hydrogen 1# operating condition was 529kg / t, a decrease of 2.40%; the solid fuel ratio under hydrogen 2# operating condition was 518.5kg / t, a decrease of 4.34%, an increase of 1.94%; the solid fuel ratio under hydrogen 3# operating condition was 510.4kg / t, a decrease of 5.83%, an increase of 1.49%; the solid fuel ratio under hydrogen 4# operating condition was 504.1kg / t, a decrease of 6.99%, an increase of 1.16%.

[0082] ②Carbon emissions (not converted to CO)

[0083] The carbon emission under the coke oven gas 1# working condition is 325.70m 3 / t, a decrease of 1.47%; the carbon emission under the coke oven gas 2# working condition is 320.37m 3 / t, a decrease of 3.08%, and an increase of 1.61%; the carbon emission under the coke oven gas 3# working condition is 314.82m 3 / t, a decrease of 4.76%, an increase of 1.68%; the carbon emission under the 4# coke oven gas condition is 309.00m 3 / t, a decrease of 6.52%, and an increase of 1.76%; the carbon emission under the 5# coke oven gas working condition is 303.23m 3 / t, a decrease of 8.27%, and an increase of 1.75%.

[0084] Carbon emissions under hydrogen 1# working condition are 319.72m 3 / t, a decrease of 3.28%; the carbon emission under hydrogen 2# working condition is 307.74m 3 / t, a decrease of 6.90%, and an increase of 3.62%; the carbon emission under hydrogen 3# working condition is 295.42m 3 / t, a decrease of 10.63%, and an increase of 3.73%; the carbon emission under the 4# coke oven gas condition is 283.11m 3 / t, a decrease of 14.35%, and an increase of 3.72%.

[0085] ③Carbon emissions (converted to CO)

[0086] The carbon emission under the coke oven gas 1# working condition is 623.09m 3 / t, a decrease of 1.00%; the carbon emission under the coke oven gas 2# working condition is 618.22m 3 / t, a decrease of 1.77%, and an increase of 0.77%; the carbon emission under the coke oven gas 3# working condition is 614.84m 3 / t, a decrease of 2.31%, and an increase of 0.54%; the carbon emission under the coke oven gas 4# working condition is 611.50m 3 / t, a decrease of 2.84%, an increase of 0.53%; the carbon emission under the 5# coke oven gas condition is 609.52m 3 / t, a decrease of 3.15%, and an increase of 0.31%.

[0087] Carbon emissions under hydrogen 1# working condition are 610.88m 3 / t, a decrease of 2.94%; the carbon emission under hydrogen 2# working condition is 595.05m 3 / t, a decrease of 5.45%, and an increase of 2.51%; the carbon emission under hydrogen 3# working condition is 581.96m 3 / t, a decrease of 7.53%, and an increase of 2.08%; the carbon emission under the 4# coke oven gas condition is 571.03m 3 / t, a decrease of 9.27%, and an increase of 1.74%.

[0088] Table 6 Evaluation table

[0089]

[0090] It can be seen from Table 6 that in this example, the optimal injection rate of coke oven gas 3# and hydrogen 3# is the optimal injection rate, that is, the optimal injection rate of coke oven gas is 90m 3 / t, the optimum injection rate of hydrogen is 180m 3 / t. If you want to make the result more accurate, you only need to reduce the gradient of the hydrogen-rich gas injection volume under each working condition and repeat the above calculation process. Ironmaking plants can also multiply C1 to C3 by the attention coefficients R1 to R3 according to their own needs. The larger the attention coefficient, the more stringent the requirements in this aspect (solid fuel consumption, carbon emissions), R1+R2+R3=3.

[0091] In summary, the method provided by the present invention can determine the optimal value of the amount of hydrogen-rich gas injected into the hydrogen-rich blast furnace. Under this injection scheme, the injected hydrogen-rich gas can be efficiently utilized, and the carbon reduction and emission reduction effects produced are significant, which provides a scientific basis for iron and steel plants to coordinate the transportation of hydrogen-rich gas and plan the injection amount of hydrogen-rich gas.

[0092] Matters not described in detail in the present invention are all known technologies.

[0093] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for determining the optimal amount of hydrogen-rich gas to be injected based on an energy quality model of a hydrogen-rich blast furnace, characterized in that: The method comprises the following steps: S1. According to the material flow and energy flow properties inside the blast furnace, an energy-mass balance model of a hydrogen-rich blast furnace is constructed, which includes material balance calculation, heat balance calculation, and theoretical combustion temperature calculation model; S2. Enter the initial conditions of the hydrogen-rich blast furnace energy and mass balance model constructed in step S1; S3, adjusting the iterative hydrogen utilization rate and theoretical combustion temperature parameters according to the initial conditions in step S2; S4, based on the material balance relative error and heat loss constraint conditions obtained by theoretical calculation in step S3, specify the constraint conditions in the subsequent prediction process; S5. According to the constraint conditions obtained in step S4, the amount of hydrogen-rich gas injection is increased while the amount of solid fuel is reduced; S6. Based on the calculation result of step S5, obtain the solid fuel ratio and carbon emission under each injection system; S7. Determine the optimal amount of hydrogen-rich gas to be injected into the hydrogen-rich blast furnace based on the solid fuel ratio and carbon emission under each injection system obtained in step S6.

2. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: In step S1, the energy and mass balance model of the hydrogen-rich blast furnace adds a hydrogen-rich gas input terminal to the material balance part, the heat balance adopts the first total heat balance, and the theoretical combustion temperature model additionally adds the methane combustion exothermic term in the hydrogen-rich gas.

3. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: In step S2, the initial conditions include raw fuel data, blast parameters, preset molten iron composition, mixed ore ratio, and oxygen enrichment rate original parameters.

4. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: The step S3 specifically includes: firstly assuming a hydrogen utilization rate to obtain the relative proportion of H2 and H2O in the specific furnace top gas, and calculating the theoretical hydrogen utilization rate after obtaining the complete furnace top gas composition, and repeatedly iterating the preset value of the hydrogen utilization rate so that the two hydrogen utilization rates are equal; the theoretical combustion temperature calculation requires a preset temperature, and then the theoretical combustion temperature is calculated by the temperature, and the preset temperature is continuously iterated so that the two temperatures are equal. The preset temperature at this time is the theoretical combustion temperature.

5. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 4, characterized in that: The calculation formula for hydrogen utilization rate and theoretical combustion temperature is as follows: Where: is the hydrogen utilization rate; η CO is the carbon monoxide utilization rate; T f is the theoretical combustion temperature, °C; is the heat released by the combustion of coke at the tuyere, kJ / tHM; Q fuel is the heat released by the combustion of the injected fuel, kJ / tHM; Q Coke is the sensible heat brought in by coke, kJ / tHM; Q H Sensible heat brought in by hydrogen-rich gas, kJ / tHM; Q W The heat consumed by the reaction between fuel and water in the blast, kJ / tHM; Q Coke-decom is the heat of decomposition and volatilization of pulverized coal, kJ / tHM; is the heat released by the combustion of methane in hydrogen-rich gas, kJ / tHM; Q r-slag is the slag forming heat, kJ / tHM; is the average heat capacity of gas in the tuyere vortex zone, kJ / (℃·m 3 ); is the gas volume in the tuyere vortex zone, m 3 / tHM;C a_i is the average heat capacity of the ash content of fuel i, i is coke or coal powder, kJ / (℃·kg); m a_i is the ash content of fuel i, kg / tHM; C w is the average heat capacity of unburned coal powder, kJ / (℃·kg); m w is the amount of unburned coal powder, kJ / tHM.

6. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 5, characterized in that: In step S4, the relative error of material balance is controlled within 0.1%; the heat loss is guaranteed to be within 4×10 5 kJ / tHM or above.

7. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: The step S5 specifically includes: increasing the injection amount of hydrogen-rich gas in a stepwise manner, while reducing the amount of solid fuel, and limiting the reduction range of the amount of solid fuel with heat loss as a constraint condition.

8. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: In step S6, carbon emissions only consider direct carbon emissions, including two algorithms: only calculating blast furnace top CO2 emissions and converting CO into carbon emissions; the relevant calculation formula is as follows: Where: To calculate only the carbon emissions from the blast furnace top CO2 emissions, m 3 / tHM; is the volume of CO2 in the hydrogen-rich blast furnace top gas, m 3 / tHM; is the carbon emission after conversion to CO, m 3 / tHM; 0.719 is the ratio of the calorific value of CO and C; is the volume of CO in the hydrogen-rich blast furnace top gas, m 3 / tHM.

9. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 1, characterized in that: The step S7 specifically includes: after obtaining the solid fuel usage and carbon emission data through theoretical calculation, jointly establishing the gradient evaluation parameter E C It is used to evaluate the necessity of continuing to inject additional hydrogen-rich gas, and in the process of increasing the amount of hydrogen-rich gas injection, the last one makes E C The injection amount that meets the conditions is the optimal injection amount of hydrogen-rich gas.

10. The method for determining the optimal amount of hydrogen-rich gas to be injected based on the energy quality model of a hydrogen-rich blast furnace according to claim 9, characterized in that: E C The parameter calculation method is: E C =C1+C2+C3 Where: when the reduction in solid fuel consumption is less than 75% of the maximum reduction, C1 takes 0, otherwise it takes 1; when the reduction in the first type of carbon emissions decreases, C2 takes 0, otherwise it takes 1; when the reduction in the second type of carbon emissions is less than 60% of the maximum reduction, C3 takes 0, otherwise it takes 1; If the gradient evaluation parameter E C ≥2, the hydrogen-rich gas injection rate HGI i It is more appropriate to continue to increase the injection rate of hydrogen-rich gas. If the next gradient injection rate makes E C <2, then the HGI of this gradient i For the optimal amount of hydrogen-rich gas to be sprayed.

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