Method and apparatus for oxygen coal gun and oxygen distribution in blast

Abstract

The application discloses a method and equipment for distributing oxygen in an oxygen-coal gun and blast, which comprises the following steps: establishing a geometric model of the oxygen-coal gun, a direct blowing pipe, a tuyere and a revolving zone, determining a gas phase basic control equation and a control equation between the gas phase and particles, defining equation iteration parameters based on current distribution data of oxygen in the oxygen-coal gun and the blast, and iterating the two equations, and then screening a first fly ash mass fraction before combustion, a second fly ash mass fraction after combustion, a high-temperature heat flow temperature and a tuyere surface temperature of the revolving zone from the converged calculation results; determining a pulverized coal burnout rate according to the first fly ash mass fraction and the second fly ash mass fraction, and determining a heat flow density according to the high-temperature heat flow temperature and the tuyere surface temperature; and determining whether the current distribution data is optimal distribution data according to the pulverized coal burnout rate and the heat flow density. Production according to the optimal distribution data can not only improve fuel utilization rate, but also avoid tuyere melting loss and erosion, and thus yield and income are increased.

Description

Technical Field

[0001] This application belongs to the field of blast furnace ironmaking technology, and particularly relates to a method and equipment for oxygen distribution in an oxygen lance and blast furnace. Background Technology

[0002] The steel industry is a crucial foundational industry in the national economy, and also a major contributor to energy consumption and carbon emissions. Among these processes, blast furnace ironmaking ranks first in energy consumption and carbon emissions, representing a significant potential area for future energy conservation and emission reduction. Blast furnace pulverized coal injection (CPGE) technology is a vital green and low-carbon technology for modern blast furnaces and a central element in optimizing the ironmaking system structure. This technology not only adjusts the thermal regime of the blast furnace but, more importantly, can replace coke as a heating and reducing agent, effectively reducing smelting energy consumption and carbon emissions, lowering pig iron costs, and aligning with the national steel industry's green and low-carbon development strategy. With the continuous expansion of low-cost oxygen production technology, blast furnace oxygen-enriched blast furnace injection technology has greater advantages in cost savings, carbon emission reduction, and achieving sustainable development in the steel industry. Currently, there are two main methods for oxygen enrichment in this technology: one is to heat cold air through a hot blast stove and inject industrial oxygen into the outlet duct to achieve oxygen enrichment; the other is to modify the structure of the traditional pulverized coal lance, injecting CPGE in the inner ring and blowing oxygen in the outer ring to achieve oxygen enrichment in the pulverized coal lance. In high-oxygen-enriched smelting, coupling two oxygen-enrichment methods is an inevitable choice.

[0003] When combining the two oxygen enrichment methods of forced draft oxygen enrichment and oxygen-coal gun oxygen enrichment, how to increase production and revenue is an urgent problem to be solved. Summary of the Invention

[0004] The embodiments of this application provide a method and equipment for distributing oxygen in the oxy-fuel gun and the blower, thereby determining the optimal oxygen distribution scheme in the oxy-fuel gun and the blower to at least a certain extent, thereby increasing production and revenue.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to a first aspect of the embodiments of this application, a method for oxygen distribution in an oxygen lance and a blower is provided, the method comprising:

[0007] Establish geometric models of the oxygen lance, direct-fire pipe, tuyeres, and vortex zone;

[0008] The computational domain of the geometric model is meshed, and the basic governing equations for the gas phase and the governing equations between the gas phase and particles are determined based on the mesh.

[0009] The gas-phase basic control equations are discretized, and the equation iteration parameters are defined based on the current distribution data of oxygen in the oxygen lance and the blower. The equation iteration parameters include material properties, boundary conditions, initial conditions, time step and residual value.

[0010] Based on the equation iteration parameters, the basic gas phase control equation and the control equation between the gas phase and particles are iterated until the calculation results converge.

[0011] The first fly ash mass fraction before combustion, the second fly ash mass fraction after combustion, the high-temperature heat flow temperature, and the tuyer surface temperature of the vortex zone are selected from the converged calculation results.

[0012] The pulverized coal combustion rate is determined based on the first fly ash mass fraction and the second fly ash mass fraction, and the heat flux density is determined based on the high-temperature heat flux temperature and the tuyer surface temperature.

[0013] The current allocation data is determined as optimal based on the pulverized coal burnout rate and the heat flux density.

[0014] In some embodiments of this application, based on the foregoing scheme, the meshing of the computational domain of the geometric model includes:

[0015] The gas phase region and gas-solid phase region in the computational domain of the geometric model are meshed using a structured mesh.

[0016] In some embodiments of this application, based on the foregoing scheme, the basic governing equations of the gas phase include the gas phase mass equation, gas phase momentum equation, gas phase energy equation, gas phase composition equation, turbulent kinetic energy equation, and turbulent dissipation rate equation; the governing equations between the gas phase and particles include the mass equation between the gas phase and particles, the momentum equation between the gas phase and particles, and the energy equation between the gas phase and particles.

[0017] In some embodiments of this application, based on the aforementioned scheme, the boundary conditions are as follows: the oxygen-coal gun and the swirling zone are fluid-structure interaction boundaries, the direct-blowing pipe is a fluid boundary, the inlet of the blower and the oxygen-coal gun is a velocity inlet boundary condition, and the outlet of the blower and the oxygen-coal gun is a free outflow boundary condition.

[0018] In some embodiments of this application, based on the foregoing scheme, the initial conditions include: the blower velocity at the junction of the direct-blowing pipe and the air outlet, the injection velocity of the airflow inside the oxy-coal lance, and the initial mass of the pulverized coal flow inside the oxy-coal lance; the equation iteration parameters defined based on the current distribution data of oxygen content in the oxy-coal lance and the blower include:

[0019] Based on the current distribution data of oxygen in the oxygen lance and the blower, the blower speed, the injection speed, and the initial mass are determined.

[0020] In some embodiments of this application, based on the foregoing scheme, the initial conditions are as follows: the blowing velocity at the junction of the direct blowing pipe and the air outlet is 119.34 m / s, the temperature at the inlet of the direct blowing pipe is 1473 K, the blowing velocity of the airflow in the oxygen-coal lance is 2.55 m / s, the temperature of the gas in the oxygen-coal lance is 298 K, the initial temperature of the coal powder flow in the oxygen-coal lance is 323 K, and the initial mass of the coal powder flow is 0.64 kg / s.

[0021] In some embodiments of this application, based on the foregoing scheme, the pulverized coal burnout rate is determined according to the following formula:

[0022] Burnout = (1-m) a，0 / m a ) / (1-m a，0 );

[0023] Where, m a，0 The second fly ash mass fraction, m a This refers to the second fly ash mass fraction;

[0024] The heat flux density is determined according to the following formula:

[0025] Q = h(T) w -T s );

[0026] Where Q is the heat flux density during convective heat transfer between the heat flux and the air outlet, h is the convective heat transfer coefficient, and T w T is the surface temperature of the air vent. s The high-temperature heat flux temperature is mentioned above.

[0027] In some embodiments of this application, based on the foregoing scheme, determining whether the current allocation data is the optimal allocation data according to the pulverized coal burnout rate and the heat flux density includes:

[0028] Obtain the baseline pulverized coal burnout rate and baseline heat flux density when the oxygen content in the oxygen lance is zero;

[0029] The rate of change of pulverized coal burnout rate is determined based on the pulverized coal burnout rate and the benchmark pulverized coal burnout rate.

[0030] The rate of change of heat flux density is determined based on the heat flux density and the reference heat flux density;

[0031] The values ​​of the evaluation parameters are determined based on the change rate of pulverized coal burnout rate, the change rate of heat flux density, and the pre-set calibration coefficient.

[0032] If the value of the evaluation parameter meets the conditions, determine whether the current allocation data is the optimal allocation data.

[0033] In some embodiments of this application, based on the foregoing scheme, the value of the evaluation parameter is determined according to the following formula:

[0034] D = a × ΔBurnout ÷ ΔQ;

[0035] Where D is the value of the evaluation parameter, α is the calibration coefficient, ΔBurnout is the rate of change of the pulverized coal burnout rate, and ΔQ is the rate of change of the heat flux density.

[0036] According to a second aspect of the embodiments of this application, an apparatus for distributing oxygen in an oxy-fuel blast furnace and a blower is provided, comprising a processor and a memory, wherein the memory stores computer program instructions executable by the processor, and when the processor executes the computer program instructions, it implements the instructions for the method described in any of the first aspects above.

[0037] In this application, a geometric model of the oxy-fuel lance, direct-fire pipe, tuyeres, and swirling zone is established. The computational domain of the geometric model is meshed, and the basic gas-phase control equation and the control equation between the gas phase and particles are determined based on the mesh. The basic gas-phase control equation is discretized, and equation iteration parameters are defined based on the current distribution data of oxygen in the oxy-fuel lance and the blower. The equation iteration parameters include material properties, boundary conditions, initial conditions, time step, and residual values. The basic gas-phase control equation and the control equation between the gas phase and particles are iterated based on the equation iteration parameters until the calculation results converge. From the converged calculation results, the first fly ash mass fraction before combustion, the second fly ash mass fraction after combustion, the high-temperature heat flux temperature, and the tuyeres surface temperature are selected. The pulverized coal burnout rate is determined based on the first fly ash mass fraction and the second fly ash mass fraction, and the heat flux density is determined based on the high-temperature heat flux temperature and the tuyeres surface temperature. The current distribution data is determined to be the optimal distribution data based on the pulverized coal burnout rate and the heat flux density. Production based on this optimal allocation data can not only improve fuel utilization but also avoid tuyer erosion and thus increase production and revenue.

[0038] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0040] Figure 1 A flowchart illustrating a method for distributing oxygen in an oxygen lance and blower in one embodiment is shown.

[0041] Figure 2 A detailed schematic diagram of the geometric model in one embodiment is shown;

[0042] Figure 3 This diagram illustrates the change in pulverized coal burnout rate after varying the oxygen injection rate in the oxy-fuel lance in one embodiment.

[0043] Figure 4 This diagram illustrates the temperature change along the centerline of the pulverized coal stream when the oxygen injection rate in the oxy-coal lance changes in one embodiment.

[0044] Figure 5 A block diagram of an apparatus for distributing oxygen in a coal blast furnace and a blower is shown in one embodiment.

[0045] Figure 6 A schematic diagram of the structure of the oxygen lance and the oxygen distribution device in the blower is shown in one embodiment. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0048] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0049] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0050] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0051] like Figure 1 As shown, a method for distributing oxygen in an oxygen lance and a blower is provided, which may include the following steps 101 to 107.

[0052] In step 101, a geometric model of the oxygen lance, direct-fire pipe, tuyeres, and vortex zone is established.

[0053] Understandably, in order to develop blast furnace oxygen-enriched blast injection technology and achieve energy conservation, emission reduction, increased production and revenue, many ironmaking workers have been studying how to improve the oxygen enrichment rate, but they have neglected how to determine a reasonable distribution system of oxygen in the blast furnace and the oxygen content in the blast when the oxygen enrichment rate is constant.

[0054] It should be noted that, on the one hand, with the increased oxygen content in the oxy-fuel lance, the pulverized coal ejected from the central coal tube is enveloped by more oxygen molecules, resulting in efficient mixing of pulverized coal and oxygen and superior kinetic conditions. This leads to better combustion within a limited time, shortens the combustion reaction duration, and ensures more complete combustion, thus improving the pulverized coal burnout rate and fundamentally reducing pulverized coal consumption. On the other hand, the increased intensity of the combustion reaction raises the temperature of the hot spots in front of the tuyeres, enhancing the melting and erosion effect on the tuyeres (in this application, the surface heat flux density of the tuyeres is used to represent the degree of erosion). The blast furnace tuyeres are a crucial component in blast furnace ironmaking, and their service life is key to stable and high blast furnace production.

[0055] Therefore, it is necessary to determine the optimal distribution scheme of oxygen in the oxy-fuel gun and the blast furnace so that the pulverized coal combustion rate and the degree of tuyere erosion are maintained at a state that is most conducive to generating revenue.

[0056] Figure 2 A detailed schematic diagram of the geometric model in one embodiment is shown, such as Figure 2 As shown, the geometric model includes an oxygen lance, a direct-fire pipe, an air inlet, and a swirling zone. The oxygen lance can be a coaxial oxygen lance, and the oxygen lance can be modeled according to its external shape and structure.

[0057] The geometry of the swirling zone is determined by the calculation formula for the swirling zone structure of the wind tunnel developed by Japanese professor M. Hatano. The following are the calculation formulas for the depth, width, height, volume, and penetration factor of the swirling zone:

[0058] Dr = 0.409 × PF 0.693 ×Dt

[0059]

[0060]

[0061] Vr = 0.53 × Dr × Wr × Hr

[0062]

[0063] Where Dr is the depth of the swirling zone, in meters; Dt is the diameter of the air outlet, in meters; PF is the penetration factor of the swirling zone; Wr is the width of the swirling zone, in meters; Hr is the height of the swirling zone, in meters; and Vr is the volume of the swirling zone, in cubic meters. 3 ρ0 represents the density of the gas in the furnace belly, in kg·m³. -3 ;ρ s The true density of coke is expressed in kg·m³. -3 ;q v The volumetric flow rate of the air outlet is expressed in cubic meters (m³). 3 ·s -1 ;T f P represents the theoretical combustion temperature in the vortex zone, in Kelvin (K). b D represents the blower pressure, in kPa. p The coke particle size at the air outlet is measured in mm; S t Total area of ​​the air vent, in meters. 2 .

[0064] In step 102, the computational domain of the geometric model is meshed, and the basic governing equations of the gas phase and the governing equations between the gas phase and particles are determined based on the mesh.

[0065] In some embodiments, a structured mesh can be used to divide the gas phase region and the gas-solid phase region in the computational domain of the geometric model into meshes, so as to determine the basic governing equations of the gas phase based on the mesh of the gas phase region, and to determine the governing equations between the gas phase and particles based on the mesh of the gas-solid phase region.

[0066] In some embodiments, the basic governing equations for the gas phase include the gas phase mass equation, gas phase momentum equation, gas phase energy equation, gas phase composition equation, turbulent kinetic energy equation, and turbulent dissipation rate equation; the governing equations between the gas phase and particles include the gas phase and particle mass equation, the gas phase and particle momentum equation, and the gas phase and particle energy equation.

[0067] Specifically, the following formulas can be used to determine the gas phase mass equation, gas phase momentum equation, gas phase energy equation, gas phase component equation, turbulent kinetic energy equation, turbulent dissipation rate equation, mass equation between gas phase and particles, momentum equation between gas phase and particles, and energy equation between gas phase and particles:

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] Where, m p The mass of the particles is expressed in kg; u p The velocity of the particles, in m·s -1 ;d p C represents particle diameter in meters (m). D T is the drag coefficient; g Gas temperature, unit K; T p Particle temperature, unit K; H reac Heat of reaction, unit: J·kg -1 A p Particle surface area, in m² 2 ;ε p denoted as emissivity of the particle; i is the radiation intensity, in W·m. -2 ·s -1 ;σ B Boltzmann constant; ρ is the gas density, in kg·m³.-3 U is the velocity of the gas, in m·s. -1 ;n p Number of particles per unit volume, in meters (m). -3 ; represents the particle mass conversion rate, in kg·s -1 μ is the dynamic viscosity, in Pa·s; i ρ is turbulent viscosity, in Pa·s; P is pressure, in Pa; k is turbulent kinetic energy, in m³ / s. 2 ·s -2 ;f D H represents the drag force of pulverized coal, in N; H represents enthalpy, in J·kg. -1 λ is the thermal conductivity, in W·m. -1 ·K -1 C p Specific heat capacity of particles, unit J·kg -1 ·K -1 q represents the heat flux of the particle, in W; Y i W represents the mass fraction of component i; i The reaction rate of component i is expressed in kg·m³. -3 ·s -1 Γi is the diffusion coefficient of component i; σ k σ ε All are turbulence model constants; C1 and C2 are also turbulence model constants; ε is the turbulence dissipation rate, in m³. 2 ·s -3 C μ T is an empirical constant and can be 0.09; rad The temperature within the grid.

[0079] In step 103, the basic control equations of the gas phase are discretized, and the equation iteration parameters are defined based on the current distribution data of oxygen in the oxygen lance and the blower. The equation iteration parameters include material properties, boundary conditions, initial conditions, time step and residual value.

[0080] It is understandable that discretization can define the grid as points, and by setting the equation iteration parameters and iteration, it is possible to calculate from the starting point to the ending point and finally obtain the calculation result.

[0081] In practice, you can first set the boundary conditions and initial conditions, then define the material properties such as pulverized coal and oxygen, and finally set the time step and residual value.

[0082] In some embodiments, the boundary conditions are as follows: the oxygen lance and the swirling zone are fluid-structure interaction boundaries, the direct-blowing pipe is a fluid boundary, the inlet of the blower and the oxygen lance is a velocity inlet boundary condition, and the outlet of the blower and the oxygen lance is a free outflow boundary condition.

[0083] The initial conditions include: the air velocity at the junction of the direct blowing pipe and the air outlet, the oxygen injection velocity in the oxygen lance, and the initial mass of the coal powder flow in the oxygen lance; the equation iteration parameters are defined based on the current distribution data of oxygen in the oxygen lance and the air, including: determining the air velocity, injection velocity, and initial mass based on the current distribution data of oxygen in the oxygen lance and the air.

[0084] The current allocation data refers to the current oxygen content in the oxy-fuel gun and the current oxygen content in the blower. The sum of the current oxygen content in the oxy-fuel gun and the current oxygen content in the blower is a constant. When the current oxygen content in the oxy-fuel gun is higher, the current oxygen content in the blower is correspondingly lower.

[0085] Specifically, the initial conditions can be: the blowing velocity at the junction of the direct blowing pipe and the air outlet is 119.34 m / s, the inlet temperature of the direct blowing pipe is 1473 K, the oxygen injection velocity in the oxygen lance is 2.55 m / s, the gas temperature in the oxygen lance is 298 K, the initial temperature of the pulverized coal flow in the oxygen lance is 323 K, and the initial mass of the pulverized coal flow is 0.64 kg / s.

[0086] In some embodiments, the residual value can be set to 1×10. -5 The residual curve for energy is 1×10 -6 .

[0087] In step 104, the basic control equations of the gas phase and the control equations between the gas phase and particles are iterated based on the equation iteration parameters until the calculation results converge.

[0088] In the implementation process, the SIMPLE algorithm can be used for calculation, and the pressure and gradient can be calculated using the PRESTO and Least Square Cell Based methods respectively in spatial discretization.

[0089] In step 105, the mass fraction of the first fly ash before combustion, the mass fraction of the second fly ash after combustion, the high-temperature heat flow temperature, and the surface temperature of the tuyeres are selected from the converged calculation results.

[0090] Understandably, the calculation result corresponds to the data of the current allocation. In order to determine whether the current allocation data is the optimal allocation data, it is necessary to filter out the first fly ash mass fraction, the second fly ash mass fraction after combustion, the high-temperature heat flux temperature, and the tuyer surface temperature to calculate the pulverized coal burnout rate and heat flux density.

[0091] In step 106, the coal pulverization rate is determined based on the first fly ash mass fraction and the second fly ash mass fraction, and the heat flux density is determined based on the high-temperature heat flux temperature and the tuyer surface temperature.

[0092] In some embodiments, the pulverized coal burnout rate can be determined according to the following formula:

[0093] Burnout = (1-m) a，0 / m a ) / (1-m a，0 );

[0094] Where, m a，0 The second fly ash mass fraction, m a The second fly ash mass fraction;

[0095] Heat flux density can be determined using the following formula:

[0096] Q = h(T) w -T s );

[0097] Where Q is the heat flux density during convective heat transfer between the heat flux and the air outlet, h is the convective heat transfer coefficient, and T w T represents the surface temperature of the air vent. s This refers to the high-temperature heat flow temperature.

[0098] In the implementation process, the calculation formula for pulverized coal burnout rate can be written into the post-processing software. After CFD-ICEM performs post-processing on the calculation results, a trace graph of the pulverized coal burnout rate is obtained, as shown below. Figure 3 The diagram shows the change in pulverized coal combustion rate after varying the oxygen injection rate in the oxy-fuel lance, along with the results of parameters such as temperature. Figure 4 The diagram shows the temperature change along the center line of the pulverized coal stream when the oxygen injection rate changes in the oxy-coal lance.

[0099] In step 107, it is determined whether the current allocation data is the optimal allocation data based on the pulverized coal burnout rate and heat flux density.

[0100] In practical implementation, the baseline pulverized coal burnout rate and baseline heat flux density can be obtained when the oxygen content in the pulverized coal lance is zero; the pulverized coal burnout rate change rate is determined based on the pulverized coal burnout rate and the baseline pulverized coal burnout rate; the heat flux density change rate is determined based on the heat flux density and the baseline heat flux density; the values ​​of the evaluation parameters are determined based on the pulverized coal burnout rate change rate, the heat flux density change rate, and the pre-set calibration coefficient; and if the values ​​of the evaluation parameters meet the conditions, it is determined whether the current allocation data is the optimal allocation data.

[0101] The values ​​of the evaluation parameters are determined according to the following formula:

[0102] D = a × ΔBurnout ÷ ΔQ;

[0103] Where D is the value of the evaluation parameter, α is the calibration coefficient, ΔBurnout is the rate of change of pulverized coal burnout rate, and ΔQ is the rate of change of heat flux density.

[0104] The calibration coefficient can be set according to the company's real-time coal powder price and the lifespan of the tuyere. A higher coefficient indicates that the benefits of improving the coal powder burnout rate are higher than the cost of replacing the tuyere, while a lower coefficient indicates that the benefits of improving the coal powder burnout rate are insufficient to cover the cost of replacing the tuyere.

[0105] Understandably, the D parameter can be used to evaluate the advantages and disadvantages of different oxygen distribution strategies in the oxy-fuel lance and blast furnace on ironmaking production. The closer the D parameter is to the calibration coefficient, the more reasonable the current distribution data. When multiple D parameters are obtained based on different distribution data, the distribution data corresponding to the D parameter closest to the calibration coefficient can be taken as the optimal distribution data. When using the optimal distribution data for production, the advantages (increased pulverized coal combustion rate) and disadvantages (reduced tuyeres lifespan) of increasing the oxygen supply to the oxy-fuel lance can be balanced.

[0106] This application fully considers the dual impact mechanism of increasing oxygen content in the oxy-coal lance on blast furnace smelting under a fixed total oxygen enrichment rate. It scientifically evaluates the effects of changing oxygen distribution under two different oxygen enrichment methods on parameters such as pulverized coal burnout rate, tuyere inlet temperature, and tuyere heat flux density under high oxygen enrichment conditions. This leads to improvements in the oxygen distribution scheme between the oxy-coal lance and the blast furnace, thereby increasing fuel utilization, saving energy, and generating revenue. This method has strong simulation and calculation practicality, and the obtained evaluation parameters are applicable to the current status of blast furnaces in various ironmaking plants, making it significant for understanding oxygen distribution under two different oxygen enrichment methods in high oxygen enrichment smelting.

[0107] In one embodiment, a high-oxygen blast furnace employing both oxygen-coal lance and forced draft oxygen enrichment methods was selected for numerical simulation calculation of oxygen distribution. The scheme is shown in Table 1.

[0108] Table 1 Oxygen Distribution Scheme Between Oxygen Gun and Blower

[0109]

[0110]

[0111] Establish a geometric model of the spray gun, straight nozzle, air outlet, and vortex zone, as shown in the schematic diagram below. Figure 2 As shown. The diameter of the tuyere is 130mm, the length of the tuyere is 700mm, the inclination angle of the tuyere is 3°, the diameter of the coaxial oxy-fuel lance is 38mm, the inner diameter of its oxy-fuel lance is 20mm, the angle between it and the direct-fire pipe is 8.7°, and the outlet center is located on the center line of the tuyere.

[0112] After FLUENT simulation calculations, post-processing yielded coal burnout rate trace diagrams and temperature diagrams, such as... Figure 3 and Figure 4 As shown.

[0113] The temperature at 0.2m from the air outlet under each oxygen distribution scheme was selected as the heat flux temperature in the heat flux density. The air outlet temperature was set to 350K, and the convective heat transfer coefficient was set to 153W / (m²). 2 (K)(Some data are taken from a steel mill).

[0114] Numerical simulation calculations:

[0115] The pulverized coal combustion rate #1 is 72.31%.

[0116] Pulverized coal combustion rate #2 = 73.08%; Pulverized coal combustion rate increase #1 = 1.065%;

[0117] The pulverized coal combustion rate #3 is 74.36%; the increase in pulverized coal combustion rate #2 is 1.752%.

[0118] The pulverized coal combustion rate of #4 is 75.12%; the increase in pulverized coal combustion rate of #3 is 1.022%.

[0119] The heat flux temperatures under the four schemes are as follows:

[0120] T s 1# = 1312K;

[0121] T s 2# = 1377K;

[0122] T s 3# = 1584K;

[0123] T s 4# = 1821K;

[0124] The calculated heat flux densities are as follows:

[0125] q1#=147.186kW / m 2 ;

[0126] q2#=157.131kW / m 2 The heat flux density increase is 1 = 6.757%;

[0127] q3#=188.802kW / m 2 The heat flux density increase is 2 = 20.156%.

[0128] q4#=225.063kW / m 2 The heat flux density increase was 3 = 19.206%.

[0129] The following calculation calculates the control parameter D. To simplify the calculation, the calibration coefficient is set to 1 here. In actual applications, it needs to be adjusted according to the steel plant's own situation.

[0130] D1#=0.158; D2#=0.087; D3#=0.053.

[0131] Therefore, in this example, scheme #2 should be the optimal allocation scheme.

[0132] As can be seen, the method provided in this application embodiment can determine the optimal value of oxygen in the oxy-coal lance. Under this oxygen allocation scheme, the benefits brought by the increased pulverized coal combustion rate and the reduction brought by the heat flux density received by the tuyere can be comprehensively considered and a win-win result can be obtained. This provides a scientific method for steel plants to weigh the pros and cons and plan the oxygen allocation of the oxy-coal lance and the blower.

[0133] The following describes an embodiment of the apparatus described in this application, which can be used to execute the method for distributing oxygen in the oxy-fuel lance and the blower as described in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method for distributing oxygen in the oxy-fuel lance and the blower described above in this application.

[0134] See Figure 5 The diagram shows a block diagram of the oxygen lance and the oxygen distribution device in the blower according to an embodiment of this application.

[0135] like Figure 5 As shown in the embodiment of this application, the device for oxygen distribution in the oxygen lance and blower includes: a model building unit 501, a mesh generation unit 502, an initialization unit 503, an iterative calculation unit 504, a data filtering unit 505, a parameter calculation unit 506, and a parameter evaluation unit 507. The model building unit 501 is used to build a geometric model of the oxygen lance, the direct-blowing pipe, the duct, and the vortex zone. The mesh generation unit 502 is used to mesh the computational domain of the geometric model and determine the basic gas phase control equation and the control equation between the gas phase and particles based on the mesh. The initialization unit 503 is used to discretize the basic gas phase control equation and define the equation iteration parameters based on the current oxygen distribution data in the oxygen lance and blower. The equation iteration parameters include... The system includes material properties, boundary conditions, initial conditions, time step, and residual values; an iterative calculation unit 504, used to iterate the basic control equations of the gas phase and the control equations between the gas phase and particles based on the equation iteration parameters until the calculation results converge; a data filtering unit 505, used to filter out the first fly ash mass fraction before combustion, the second fly ash mass fraction after combustion, the high-temperature heat flux temperature, and the tuyer surface temperature from the converged calculation results; a parameter calculation unit 506, used to determine the coal powder burnout rate based on the first fly ash mass fraction and the second fly ash mass fraction, and to determine the heat flux density based on the high-temperature heat flux temperature and the tuyer surface temperature; and a parameter evaluation unit 507, used to determine whether the current allocation data is the optimal allocation data based on the coal powder burnout rate and the heat flux density.

[0136] In some embodiments of this application, based on the foregoing scheme, the mesh generation unit 502 is also used to perform mesh generation on the gas phase region and gas-solid phase region in the computational domain of the geometric model using a structured mesh.

[0137] In some embodiments of this application, based on the foregoing scheme, the basic governing equations of the gas phase include the gas phase mass equation, gas phase momentum equation, gas phase energy equation, gas phase composition equation, turbulent kinetic energy equation, and turbulent dissipation rate equation; the governing equations between the gas phase and particles include the mass equation between the gas phase and particles, the momentum equation between the gas phase and particles, and the energy equation between the gas phase and particles.

[0138] In some embodiments of this application, based on the aforementioned scheme, the boundary conditions are as follows: the oxygen-coal gun and the swirling zone are fluid-structure interaction boundaries, the direct-blowing pipe is a fluid boundary, the inlet of the blower and the oxygen-coal gun is a velocity inlet boundary condition, and the outlet of the blower and the oxygen-coal gun is a free outflow boundary condition.

[0139] In some embodiments of this application, based on the aforementioned scheme, the initial conditions include: the blower speed at the junction of the direct blower and the air outlet, the oxygen injection speed in the oxygen lance, and the initial mass of the coal powder flow in the oxygen lance. The initialization unit 503 is also used to determine the blower speed, injection speed, and initial mass based on the current distribution data of oxygen in the oxygen lance and the blower.

[0140] In some embodiments of this application, based on the aforementioned scheme, the initial conditions are as follows: the blowing velocity at the junction of the direct blowing pipe and the air outlet is 119.34 m / s, the temperature at the inlet of the direct blowing pipe is 1473 K, the blowing velocity of oxygen in the oxygen-coal gun is 2.55 m / s, the temperature of the gas in the oxygen-coal gun is 298 K, the initial temperature of the coal powder flow in the oxygen-coal gun is 323 K, and the initial mass of the coal powder flow is 0.64 kg / s.

[0141] In some embodiments of this application, based on the foregoing scheme, the pulverized coal burnout rate is determined according to the following formula:

[0142] Burnout = (1-m) a，0 / m a ) / (1-m a，0 );

[0143] Where, m a，0 The second fly ash mass fraction, m a The second fly ash mass fraction;

[0144] Heat flux density is determined according to the following formula:

[0145] Q = h(T) w -T s );

[0146] Where Q is the heat flux density during convective heat transfer between the heat flux and the air outlet, h is the convective heat transfer coefficient, and T w T represents the surface temperature of the air vent. s This refers to the high-temperature heat flow temperature.

[0147] In some embodiments of this application, based on the aforementioned scheme, the parameter evaluation unit 507 is further configured to obtain the baseline pulverized coal burnout rate and baseline heat flux density when the oxygen content in the pulverized coal gun is zero; determine the pulverized coal burnout rate change rate based on the pulverized coal burnout rate and the baseline pulverized coal burnout rate; determine the heat flux density change rate based on the heat flux density and the baseline heat flux density; determine the value of the evaluation parameter based on the pulverized coal burnout rate change rate, the heat flux density change rate, and a pre-set calibration coefficient; and determine whether the current allocation data is the optimal allocation data if the value of the evaluation parameter meets the conditions.

[0148] In some embodiments of this application, based on the foregoing scheme, the values ​​of the evaluation parameters are determined according to the following formula:

[0149] D = a × ΔBurnout ÷ ΔQ;

[0150] Where D is the value of the evaluation parameter, α is the calibration coefficient, ΔBurnout is the rate of change of pulverized coal burnout rate, and ΔQ is the rate of change of heat flux density.

[0151] Based on the same inventive concept, this application also provides an oxygen lance and a device for oxygen distribution in the blower, see reference. Figure 6 The diagram shows a schematic of the structure of the oxygen lance and the oxygen distribution device in the blower according to an embodiment of this application. The oxygen lance and the oxygen distribution device in the blower include one or more memories 604, one or more processors 602, and at least one computer program (computer program instruction) stored in the memory 604 and executable on the processor 602. When the processor 602 executes the computer program, it implements the method as described above.

[0152] Among them, Figure 6In this document, a bus architecture (represented by bus 600) is used. Bus 600 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 602 and memory represented by memory 604. Bus 600 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 605 provides an interface between bus 600 and receiver 601 and transmitter 603. Receiver 601 and transmitter 603 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 602 is responsible for managing bus 600 and general processing, while memory 604 can be used to store data used by processor 602 during operation.

[0153] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing at least one computer program instruction, which is loaded and executed by a processor to perform the operation as described above.

[0154] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0155] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0156] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0157] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0158] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for oxygen distribution in an oxygen lance and a blower, characterized in that, The method includes: Establish geometric models of the oxygen lance, direct-fire pipe, tuyeres, and vortex zone; The computational domain of the geometric model is meshed, and the basic governing equations for the gas phase and the governing equations between the gas phase and particles are determined based on the mesh. The gas-phase basic control equations are discretized, and the equation iteration parameters are defined based on the current distribution data of oxygen in the oxygen lance and the blower. The equation iteration parameters include material properties, boundary conditions, initial conditions, time step and residual value. Based on the equation iteration parameters, the basic gas phase control equation and the control equation between the gas phase and particles are iterated until the calculation results converge. The first fly ash mass fraction before combustion, the second fly ash mass fraction after combustion, the high-temperature heat flow temperature, and the tuyer surface temperature of the vortex zone are selected from the converged calculation results. The pulverized coal combustion rate is determined based on the first fly ash mass fraction and the second fly ash mass fraction, and the heat flux density is determined based on the high-temperature heat flux temperature and the tuyer surface temperature. The current allocation data is determined as optimal based on the pulverized coal burnout rate and the heat flux density.

2. The method according to claim 1, characterized in that, The meshing of the computational domain of the geometric model includes: The gas phase region and gas-solid phase region in the computational domain of the geometric model are meshed using a structured mesh.

3. The method according to claim 1, characterized in that, The basic governing equations for the gas phase include the gas phase mass equation, gas phase momentum equation, gas phase energy equation, gas phase composition equation, turbulent kinetic energy equation, and turbulent dissipation rate equation; the governing equations between the gas phase and particles include the gas phase and particle mass equation, the gas phase and particle momentum equation, and the gas phase and particle energy equation.

4. The method according to claim 3, characterized in that, The boundary conditions are as follows: the oxygen-coal lance and the swirling zone are fluid-structure interaction boundaries, the direct-blowing pipe is a fluid boundary, the inlet of the blower and the oxygen-coal lance are velocity inlet boundary conditions, and the outlet of the blower and the oxygen-coal lance are free outflow boundary conditions.

5. The method according to claim 1, characterized in that, The initial conditions include: the air velocity at the junction of the direct-blowing pipe and the air outlet, the oxygen injection velocity in the oxy-coal lance, and the initial mass of the pulverized coal flow in the oxy-coal lance; the iterative parameters of the equation defined based on the current distribution data of oxygen in the oxy-coal lance and the airflow include: Based on the current distribution data of oxygen in the oxygen lance and the blower, the blower speed, the injection speed, and the initial mass are determined.

6. The method according to claim 5, characterized in that, The initial conditions are as follows: the air velocity at the junction of the direct blowing pipe and the air outlet is 119.34 m / s, the inlet temperature of the direct blowing pipe is 1473 K, the oxygen injection velocity in the oxygen lance is 2.55 m / s, the gas temperature in the oxygen lance is 298 K, the initial temperature of the pulverized coal flow in the oxygen lance is 323 K, and the initial mass of the pulverized coal flow is 0.64 kg / s.

7. The method according to any one of claims 1 to 6, characterized in that, The step of determining whether the current allocation data is the optimal allocation data based on the pulverized coal burnout rate and the heat flux density includes: Obtain the baseline pulverized coal burnout rate and baseline heat flux density when the oxygen content in the oxygen lance is zero; The rate of change of pulverized coal burnout rate is determined based on the pulverized coal burnout rate and the benchmark pulverized coal burnout rate. The rate of change of heat flux density is determined based on the heat flux density and the reference heat flux density; The values ​​of the evaluation parameters are determined based on the change rate of pulverized coal burnout rate, the change rate of heat flux density, and the pre-set calibration coefficient. If the value of the evaluation parameter meets the conditions, determine whether the current allocation data is the optimal allocation data.

8. The method according to claim 7, characterized in that, The values ​​of the evaluation parameters are determined according to the following formula: D= ɑ× Burnout÷ Q; Where D is the value of the evaluation parameter, and α is the calibration coefficient. Burnout is the rate of change in the pulverized coal burnout rate. Q is the rate of change of heat flux density.

9. A device for distributing oxygen in an oxygen blast furnace and a blower, comprising a processor and a memory, characterized in that, The memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, it implements the instructions of the method as described in any one of claims 1 to 8.

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