Method for calculating gas utilization rate by using distribution and change of lower part of blast furnace gas space

Abstract

The application discloses a method for calculating gas utilization rate by using space distribution and change of lower part of blast furnace gas. The method comprises the following steps: dividing the gas flow space of the lower part of the blast furnace into two areas, i.e. an A area and a B area, the A area is a soft melting zone of the blast furnace edge burden area, and the B area is a soft melting zone of the blast furnace center burden column area; calculating a standard gas amount of the blast furnace; according to the standard gas amount of the blast furnace, calculating the influence value of burden distribution on the gas volume space of the A area and the B area of the blast furnace, the influence value of blast wind speed on the gas volume space of the A area and the B area of the blast furnace, the influence value of oxygen enrichment and coal powder injection on the gas space change of the A area and the B area of the blast furnace; summing up the above to obtain the comprehensive change rate of the gas space of the A area of the blast furnace and the comprehensive change rate of the gas space of the B area of the blast furnace; and calculating the change of the gas utilization rate of the blast furnace according to the comprehensive change rate of the gas space of the A area of the blast furnace and the comprehensive change rate of the gas space of the B area of the blast furnace. The application can improve the gas utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of ironmaking technology, specifically relating to a method for calculating gas utilization rate by utilizing the spatial distribution and changes of gas in the lower part of a blast furnace. Background Technology

[0002] The blast furnace gas flow is generated by the consumption of nearby fuels (coke and pulverized coal) by oxygen in the hot air blown in front of the tuyere. It generally forms two main gas flows: one at the edge and one at the center. The upper blast furnace charging structure, tuyere control parameters, and injection parameters jointly promote the continuous development of the shape of the softening zone, which in turn affects the path, space, and indirect reduction utilization rate of the main gas flow between the tuyere and the softening layer. Blast furnace operation practice shows that: (1) blast furnace charging can change the space, quantity, and distribution of the two gas flows below the softening zone; (2) tuyere size and blast volume can change the space, quantity, and distribution of the two gas flows below the softening zone; (3) oxygen enrichment and volatile matter from injected pulverized coal can change the space, quantity, and distribution of the two gas flows below the softening zone.

[0003] Therefore, under the condition of ensuring blast furnace stability, guiding the blast furnace to improve the gas space and distribution below the softening zone through upper and lower adjustments can increase the indirect reduction rate of gas and provide a technical method for reducing blast furnace fuel consumption. In summary, it is necessary to explore the impact of changes in the gas flow space and flow rate of the two gas streams at the center and edge of the blast furnace on the indirect reduction of the blast furnace, in order to guide the blast furnace in improving gas utilization efficiency.

[0004] For example, Chinese patent application number 201210208357.X provides a method for predicting blast furnace gas utilization rate, including: inputting the physical properties of ore and coke and gas parameters; obtaining the diffusion coefficient in the layered structure; calculating the reduction reaction rate of iron ore and the dissolution reaction rate of coke based on the diffusion coefficient; obtaining the composition distribution of gas based on the reduction reaction rate and the dissolution reaction rate of coke; determining whether the obtained gas composition converges; if not, recalculating the reduction reaction rate of iron ore and the dissolution reaction rate of coke; otherwise, predicting the gas utilization rate based on the gas composition. This method is mainly used to predict blast furnace gas utilization rate without coupling parameters such as the movement of the furnace charge and the temperature field inside the blast furnace. It can predict the gas utilization rate based on parameters such as the initial gas composition, temperature, and furnace charge structure. However, it does not involve quantitative analysis of the impact of gas spatial changes below the softening zone on the blast furnace gas utilization rate.

[0005] For example, Chinese patent application number 201210408620.X provides a method for calculating the gas utilization efficiency of a blast furnace under conditions of adding highly reactive coke. It can also calculate the direct and indirect reduction degrees in the high-temperature zone and heat reserve zone under the same conditions. The total direct reduction degree r of the blast furnace is... d For: blast furnace gas utilization rate η COThe method is designed to accurately calculate the direct reduction degree and gas utilization rate in blast furnace smelting under the above raw material conditions, guiding blast furnace production. This method is also applicable to traditional blast furnaces using metallurgical coke. This invention does not involve using parameters such as material distribution and tuyeres to determine changes in blast furnace gas utilization rate.

[0006] For example, Chinese patent application number 201510319096.2 provides a method for improving blast furnace gas utilization. Its distribution matrix is ​​shown in the figure, where C represents coke, O represents ore, and the inclination angle of the distribution chute is divided into 10 levels, 9 levels, 8 levels, 7 levels, 6 levels, and 5 levels, corresponding to angles of 40.5°, 38.7°, 36.7°, 34.5°, 31.8°, and 28.5°, respectively. This invention improves blast furnace gas utilization by distributing materials, but does not address the impact of material distribution on the amount of gas space and gas distribution in the lower part of the blast furnace softening zone.

[0007] In summary, existing technologies do not involve methods for quantifying and comprehensively evaluating the spatial changes of gas below the blast furnace softening zone to guide improvements in blast furnace gas utilization. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the aforementioned background technology and provide a method for calculating gas utilization rate by utilizing the spatial distribution and changes of gas in the lower part of the blast furnace. Based on the influence of blast furnace charging, tuyeres operation, and injection parameters on the gas flow distribution under the softening zone, the gas utilization rate of the blast furnace body is quantitatively analyzed, thereby reducing fuel consumption in the blast furnace.

[0009] The technical solution adopted in this invention is: a method for calculating gas utilization rate by utilizing the spatial distribution and changes of gas in the lower part of a blast furnace, comprising the following steps:

[0010] The lower gas flow space of the blast furnace is divided into two areas, A and B. Area A is the soft melting zone of the blast furnace edge and the central soft melting zone of the blast furnace.

[0011] Calculate the blast furnace reference gas volume;

[0012] Based on the blast furnace reference gas volume, calculate the impact of the charging operation on the gas volume space in blast furnace A area, the impact of the charging operation on the gas volume space in blast furnace B area, the impact of the blast wind speed on the gas volume space in blast furnace A area, the impact of the blast wind speed on the gas volume space in blast furnace B area, the impact of oxygen enrichment and pulverized coal volatiles on the gas space changes in blast furnace A area, and the impact of oxygen enrichment and pulverized coal volatiles on the gas space changes in blast furnace B area.

[0013] The comprehensive change rate of the gas space in blast furnace A area is obtained by summing the values ​​of the influence of fabric placement on the gas volume space in blast furnace A area, the influence of blast wind speed on the gas volume space in blast furnace A area, and the influence of oxygen enrichment and volatile matter of pulverized coal injection on the gas space changes in blast furnace A area. The comprehensive change rate of the gas space in blast furnace B area is obtained by summing the values ​​of the influence of fabric placement on the gas volume space in blast furnace B area, the influence of blast wind speed on the gas volume space in blast furnace B area, and the influence of oxygen enrichment and volatile matter of pulverized coal injection on the gas space changes in blast furnace B area.

[0014] The change in blast furnace gas utilization rate is calculated based on the comprehensive change rate of gas space in blast furnace A area and the comprehensive change rate of gas space in blast furnace B area.

[0015] Calculate the reference gas volume for the blast furnace:

[0016] Vg = 121%·V airr +2×VO2+V vad

[0017] Where: V air - Volumetric blast of hot air entering the furnace; Vg - Volumetric gas volume of reference coal at the front end of the blast furnace tuyeres; VO2 - Volumetric oxygenation in the reference blast furnace gas; V vad -Volume amount of volatile matter from pulverized coal injection.

[0018] The calculation of the blast furnace reference gas quantity in the above steps is for the purpose of subsequent analysis of the charging (V) burden ), blower wind speed (V) v ), Volatile matter from pulverized coal injection (V) vad The adjusted trend of gas variation in each space provides a benchmark for correction and evaluation. The benchmark gas quantity for the blast furnace is generally the average value during normal blast furnace production.

[0019] Calculate the impact of the charging material on the gas volume space in blast furnace A area, ΔVA. burden The influence of the fabric on the gas volume space in blast furnace B area, ΔVB burden :

[0020]

[0021]

[0022]

[0023] Wherein, α0 is the distribution coefficient of blast furnace gas in area A, and α0 is the distribution ratio of gas in area A when the relevant parameters reach their average values ​​during normal blast furnace production; γ S0 - Edge fabric reference load; γ S1 - Adjust the load on the edge fabric; γ C0 -Center fabric reference load; γ C1- Load after center fabric adjustment; λx - Correction coefficient.

[0024] The reason for calculating the impact of the charging load on the gas volume space in blast furnace zones A and B in the above steps is that the charging load directly affects the gas flow distribution in zones A and B. The reason for using the edge and center load variation correction coefficients corresponding to the space in zones A and B is that the spatial changes in blast furnace zones A and B are regular with the edge and center load variations. However, due to the differences in each blast furnace type, an empirical correction coefficient λx needs to be summarized to calculate Δα. X =α1-α0 and ΔVA burden .

[0025] Calculate the influence of blast wind speed on the gas volume space of blast furnace A area, ΔVA. v :

[0026]

[0027] Where: ν1 - blast velocity after changes in blast furnace air inlet area and air volume; ν0 - reference blast velocity;

[0028] ΔVAv=β·Δν / ν0

[0029] Where: β-wind speed affects the distribution coefficient of the initial gas distribution in zone A at the tuyeres; therefore, the influence of the blast wind speed on the gas volume space in zone B of the blast furnace is ΔVB. V :

[0030] ΔVBv=(1-β)·Δν / ν0

[0031] Because the spaces in zones A and B are related to the blast furnace tuyeres velocity, the above steps use β as the distribution coefficient for the influence of blast velocity on the distribution of tuyeres gas in zone A. The value of β needs to be obtained based on the actual production experience of each blast furnace. Generally, the spatial changes in zones A and B are positively correlated with blast velocity, and β decreases as the blast velocity changes. That is, the effect of blast velocity on increasing the space in zone A of the blast furnace weakens, while it increases the space in zone B. The change in blast velocity is related to the tuyeres area and the air volume.

[0032] Calculate the impact of oxygen enrichment and volatile matter from pulverized coal injection on the spatial variation of gas in blast furnace zone A, ΔVA. PCL :

[0033] ΔVA PCL =δ·(ΔV) vad +2ΔVO2) / Vg

[0034] Where: δ-ΔVA PCL The allocation coefficients in regions A and B

[0035] The increase in volatile matter content of pulverized coal is ΔV vadThe effect of oxygen enrichment on the spatial variation of gas in blast furnace B area, ΔVB PCL :

[0036] ΔVB PCL = (1-δ)·(ΔV) vad +2ΔVO2) / Vg

[0037] The reason for calculating the impact of oxygen enrichment and volatile matter from pulverized coal injection on the gas volume in blast furnace zone A in the above steps is that oxygen reacts with pulverized coal and coke at the tuyeres to generate CO, causing a surge in the gas volume at the tuyeres. The volatile matter in the pulverized coal also vaporizes, resulting in a rapid increase in the gas volume at the front end of the tuyeres, thus affecting the amount of gas formed in zone A. The value of δ needs to be determined based on the actual production experience of each blast furnace, taking into account its specific injection characteristics.

[0038] Calculate the overall spatial variation rate ΔVA of gas in blast furnace A area respectively. 总 The comprehensive change rate of gas space in blast furnace B area ΔVB 总 :

[0039] ΔVA 总 =VA burden +ΔVA v +ΔVA PCL

[0040] ΔVB 总 =VB burden +ΔVB v +ΔVB PCL

[0041] The reason for calculating the comprehensive gas space change rate of each of the above steps is that the total change in gas in areas A and B will affect the final gas utilization rate of these two areas.

[0042] Calculate the change in blast furnace gas utilization rate Δη CO :

[0043] Δη CO =σ A ·ΔVA 总 ·α+σ B ·ΔVB 总 ·(1-α)

[0044] Where, σ A - The effect of the gas volume change rate in area A on the gas utilization rate η CO Influence coefficient; σ B - The effect of gas volume change rate in Zone B on gas utilization rate η CO The influence coefficient; α-the distribution coefficient of blast furnace gas in area A.

[0045] The reason why the total change rate of gas in areas A and B affects the gas utilization rate η in the above steps is... CO Influence coefficient σ A and σ B The difference is that Zone A contains more iron-bearing furnace charge and has higher gas utilization efficiency, while Zone B contains less iron-bearing furnace charge and has lower gas utilization efficiency. The values ​​of σA and σB should be determined based on the specific conditions of the blast furnace and taken from experience.

[0046] By following the above steps and principles, the changes in gas volume in blast furnace regions A and B can be quantitatively calculated to determine the changes in blast furnace gas utilization rate, providing a method for improving blast furnace gas reduction efficiency and reducing carbon consumption.

[0047] This invention utilizes the flow and distribution characteristics of gas within a blast furnace. Based on the furnace type of a single blast furnace, it rationally quantifies the distribution ratio of blast furnace gas that affects the spatial distribution between the tuyeres and the softening zone. This guides the blast furnace to adjust the gas distribution at the tuyeres, diverting the gas to areas that are conducive to improving reduction efficiency while maintaining blast furnace stability. This increases gas utilization, reduces fuel consumption, and provides technical guidance for low-carbon blast furnace smelting.

[0048] This invention quantifies and comprehensively evaluates the changes in gas space below the blast furnace softening zone by calculating the changes in blast furnace operating parameters, and uses this to guide the blast furnace to improve gas utilization.

[0049] This invention analyzes the spatial distribution characteristics of gas below the softening zone and above the tuyere in the furnace based on the blast furnace charging conditions, tuyere air supply conditions, and the volatile matter and oxygen enrichment status of pulverized coal. When the blast furnace charging parameters, tuyere air supply parameters, and pulverized coal volatile matter parameters change, the change rate of gas space at the edge and center of the blast furnace is quantified.

[0050] This invention calculates the blast furnace gas utilization efficiency and its variation law based on the influence of the two gas flow patterns at the edge and center of the blast furnace on the blast furnace gas utilization rate.

[0051] This invention is a method for improving the gas utilization rate of a blast furnace by comprehensively evaluating the changes in the gas space and distribution below the blast furnace softening zone through operating parameters. Specifically, it involves: (1) determining the gas space distribution characteristics of the edge and center of the furnace below the softening zone and above the tuyeres based on the blast furnace charging, tuyeres feeding conditions, and oxygen enrichment conditions; (2) determining the empirical coefficients of the initial gas distribution at the edge and center of the blast furnace through blast furnace production practice, and quantifying the rate of change of the gas space at the edge and center of the blast furnace under different conditions; and (3) quantifying and calculating the blast furnace gas utilization efficiency based on the influence law and characteristics of the two gas flow patterns at the edge and center of the blast furnace on the blast furnace gas utilization rate, guiding the development of indirect reduction in the blast furnace, and reducing fuel consumption. Attached Figure Description

[0052] Figure 1 This is a schematic diagram showing the main distribution of gas flow below the softening zone of the blast furnace. Detailed Implementation

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0054] During normal blast furnace production, the hot air blown in through the tuyere burns pulverized coal and coke near the tuyere to generate initial blast furnace gas. The initial blast furnace gas is obstructed near the softening zone. Since the area below the softening zone is mainly coke and molten dripping slag and iron, when the gas in this area passes through the softening zone, it enters the solid material layer of the furnace body to reduce the iron ore charge. Therefore, the change in the gas flow rate through the softening zone, the matching of the gas flow rate and distribution location with the iron ore distribution in the material layer (the more ore, the better the gas utilization rate) will directly affect the utilization efficiency of blast furnace gas reduction.

[0055] During normal blast furnace operation, the gas produced at the tuyeres is affected by the furnace charge structure, with approximately 60-70% of the initial gas being distributed to the area near the softening zone of the furnace charge at the blast furnace edge. Figure 1 In Zone A of the blast furnace, approximately 30-40% of the initial gas is distributed to the central material column area of ​​the blast furnace's central softening zone. Figure 1 In zone B, the stability of these two gas flow regions directly affects the smooth operation of the blast furnace, while adjustments to their size will affect the gas reduction efficiency.

[0056] The radial distribution of raw materials in the blast furnace is characterized by a high proportion of ore at the edges and a high proportion of coke in the center. The average ore / coke weight ratio (O / C = γ) in the radial direction of the blast furnace is 4.5–5.5, while the ratio at the edges is 6.5–9.5, and in the center it is 2.0–4.0. This indicates that the proportion of ore in zone A is significantly higher than in zone B. Therefore, when the blast furnace is operating stably, appropriately increasing the gas flow in zone A and appropriately decreasing the gas flow in zone B is beneficial for improving the reduction utilization rate of the gas.

[0057] The reason why the gas flow space in the lower part of the blast furnace is divided into two regions, A and B, is that the structure of the furnace charge at the edge and the center of the blast furnace is different. The edge is mostly iron ore, while the center is mostly coke. Therefore, while ensuring the stability of the blast furnace gas flow, appropriately increasing the amount of gas at the edge and reducing the amount of gas at the center is beneficial to improving the utilization rate of blast furnace gas.

[0058] The main factors affecting the amount of gas in areas A and B are: fabric (V burden ), blower wind speed (V) v ), Volatile matter from pulverized coal injection (V) vad Based on the changes in these three main factors, the following calculations are performed on the changes in the gas volume in areas A and B and their impact on the utilization rate of blast furnace gas.

[0059] A method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace includes the following steps:

[0060] Step 1: Divide the gas flow space at the bottom of the blast furnace into two areas, A and B. Area A is the soft melting zone of the blast furnace edge and the material column of the soft melting zone at the center of the blast furnace.

[0061] Calculate the reference gas volume for the blast furnace:

[0062] Vg = 121%·V airr +2×VO2+V vad

[0063] Where: V air - Volumetric blast of hot air entering the furnace; Vg - Volumetric gas volume of reference coal at the front end of the blast furnace tuyeres; VO2 - Volumetric oxygenation in the reference blast furnace gas; V vad -Volume amount of volatile matter from pulverized coal injection;

[0064] Step 2: Calculate the impact of the charging material on the gas volume space of blast furnace A area, ΔVA. burden The influence of the fabric on the gas volume space in blast furnace B area, ΔVB burden :

[0065]

[0066]

[0067]

[0068] Wherein, α0 is the distribution coefficient of blast furnace gas in area A, and α0 is the distribution ratio of gas volume in area A when the relevant parameters reach the average value during normal blast furnace production, as shown in Table 7; γ S0 - Edge fabric reference load; γ S1 - Adjust the load on the edge fabric; γ C0 -Center fabric reference load; γ C1 - Load after center charge adjustment; λx - Correction coefficient. (Note: The correction coefficient varies with the load difference between blast furnace A and B zones, and relevant values ​​need to be obtained through production experience, see Table 6);

[0069] Step 3: Calculate the impact of blast wind speed on the gas volume space of blast furnace A area, ΔVA v :

[0070] Increasing the wind speed helps increase the amount of gas reaching zone B. During normal production, the blast furnace blast speed is related to the air inlet area A and the air volume V. air Related to the changes in furnace gas velocity Δν and the changes in gas volume ΔV in the inlet air surface and air volume zones:

[0071]

[0072] Where: ν1 - blast velocity after changes in blast furnace air inlet area and air volume; ν0 - reference blast velocity;

[0073] ΔVAv=β·Δν / ν0

[0074] Wherein: β-wind speed affects the distribution coefficient of the initial gas distribution in zone A at the tuyeres. This value is obtained from production experience and is shown in Table 9. Then, the influence of the blast wind speed on the gas volume space in zone B of the blast furnace is ΔVB. V :

[0075] ΔVBv=(1-β)·Δν / ν0

[0076] Step 4: Calculate the impact of oxygen enrichment and volatile matter from pulverized coal injection on the spatial variation of gas in blast furnace zone A, ΔVA. PCL :

[0077] Since both the volatile matter content of pulverized coal injection and the oxygen-enriched combustion of pulverized coal cause an instantaneous expansion of the initial gas volume at the tuyeres, the increase in volatile matter content and oxygen enrichment in blast furnace pulverized coal injection mainly leads to an increase in gas pressure and volume expansion in zone A, expressed as ΔVA. PCL This means, that is:

[0078] ΔVA PCL =δ·(ΔV) vad +2ΔVO2) / Vg

[0079] Where: δ-ΔVA PCL The allocation coefficients for regions A and B are empirical values ​​obtained from production, as shown in Table 11.

[0080] The increase in volatile matter content of pulverized coal is ΔV vad The effect of oxygen enrichment on the spatial variation of gas in blast furnace B area, ΔVB PCL :

[0081] ΔVB PCL = (1-δ)·(ΔV) vad +2ΔVO2) / Vg

[0082] Step 5: Calculate the comprehensive change rate ΔVA of the gas space in blast furnace A area. 总 The comprehensive change rate of gas space in blast furnace B area ΔVB 总 :

[0083] ΔVA 总 =VA burden +ΔVA v +ΔVA PCL

[0084] ΔVB 总 =VBburden +ΔVB v +ΔVB PCL

[0085] Step 6: Calculate the change in blast furnace gas utilization rate Δη CO :

[0086] Δη CO =σ A ·ΔVA 总 ·α+σ B ·ΔVB 总 ·(1-α)

[0087] Production practice shows that during normal blast furnace production, the change in gas utilization rate Δη CO Related to the changes in gas volume in areas A and B, where σ A - The effect of the gas volume change rate in area A on the gas utilization rate η CO Influence coefficient; σ B - The effect of gas volume change rate in Zone B on gas utilization rate η CO Influence coefficient, σ A and σ B With ΔVA 总 and ΔVB 总 The values ​​are related to production experience (see Table 12).

[0088] Example 1: Given a unit of 4117m 3 During normal blast furnace operation, the baseline gas volume is based on the following parameters related to the gas in zones A and B:

[0089]

[0090] Table 1: Reference to Initial Gas Conditions

[0091]

[0092] Table 2: Reference Fabric

[0093]

[0094] Table 3: Baseline Wind Speed ​​Parameters

[0095]

[0096]

[0097] Table 4: Volatile Matter of Baseline Oxygen-Enriched and Pulverized Coal

[0098] (1) Calculate the reference gas volume of the blast furnace according to the parameters provided in Table 1 and Table 4.

[0099] Vg = 121%·Vairr +2×VO2+V vad =121×5570+2×210+140=7103.8m 3 / min

[0100] (2) Calculate the changes in the gas space of high A and B zones after adjusting the edge and center loads.

[0101] The total load of the blast furnace is planned to be adjusted to 4.8 to 5.4. The center and edge loads will be adjusted as follows, as shown in Table 5, which shows the edge and center loads of the blast furnace after adjustment.

[0102]

[0103] Table 5: Adjusted values ​​for blast furnace edge and center loads

[0104]

[0105]

[0106] Table 6: Difference in load factor change between Zone A and Zone B Δγ S -Δγ C Table of corresponding correction coefficient λx values

[0107] As shown in Table 5: Δγ S -Δγ C = (7.0-6.9)-(3.5-3.7)=0.3, then look up 6 to find λ X =0.17, then the blast furnace Δα is obtained. X =α1-α0 has the following value:

[0108]

[0109]

[0110]

[0111] Table 7: Distribution coefficient of blast furnace reference gas quantity in area A

[0112] The blast furnace reference gas volume is 7103.8 m³. 3 / min, according to Table 7, α0 is taken as 0.7, so:

[0113]

[0114]

[0115] (3) Calculate the effect of changes in blast velocity parameters on the gas space volume in blast furnace A and B zones.

[0116]

[0117] Table 8: Wind Speed ​​Parameters

[0118] Then, by substituting the data from Tables 3 and 8 into the formula, we can obtain:

[0119]

[0120] Wind speed / m / s β 200～210 0.8 210～220 0.78 220～230 0.76 230～240 0.72 240～250 0.68 250～260 0.62

[0121] Table 9: Empirical values ​​of the influence of wind speed variation on the distribution coefficient β of gas in area A

[0122] From Table 9, we can find β = 0.62. Substituting 2.0 m / s into the equation, we can obtain the effect of wind speed change on the gas space in area A:

[0123] ΔVAv=β·Δν / ν0

[0124] = 0.62 × (-2.0) / (7103.8 / (0.4621 × 60))

[0125] = -0.48%

[0126] Therefore, the impact of wind speed change on the gas space in area B is:

[0127] ΔVBv=(1-β)·Δν / ν0

[0128] = (1-0.62)×(-2.0) / (7103.8 / (0.4621×60))

[0129] = -0.30%

[0130] (4) Calculate the influence of oxygen enrichment and volatile matter from pulverized coal injection on the gas volume space of blast furnace A zone, ΔV. PCL

[0131]

[0132] Table 10: Current oxygen-enriched and pulverized coal injection volatile matter parameters of the blast furnace

[0133] From Table 10, we can see that ΔV vad =35m 3 / min, ΔVO2=141m 3 / min,

[0134] Vg = 7103.8m 3 The calculation by / min yields:

[0135] (ΔVvad+2ΔVO2) / Vg=(35+2×141) / 7103.8

[0136] =4.46%

[0137] From Table 11, we know that δ = 0.84, therefore:

[0138] ΔVA PCL =δ·(ΔV) vad +2ΔVO2) / Vg

[0139] =0.84 × 4.46%

[0140] =3.75%

[0141] ΔVB PCL = (1-δ)·(ΔV) vad +2ΔVO2) / Vg

[0142] = (1-0.84)×4.46%

[0143] =0.71%

[0144] (ΔVvad+2ΔVO2) / Vg δ 0.5 0.75 1％ 0.75 1.50％ 0.76 2.00％ 0.76 2.50％ 0.77 3.00％ 0.78 3.50％ 0.79 4.00％ 0.81 4.50％ 0.84 5.00％ 0.88

[0145] Table 11: Empirical values ​​of the influence of changes in oxygen enrichment of volatile matter in pulverized coal on the increase of the distribution coefficient δ of coal gas in zones A and B.

[0146] (5) Calculate the comprehensive change rate ΔVA of the gas space in blast furnace A and B zones. 总

[0147] In summary, under the combined effects of material feeding, blast velocity, and injection, the volume change rate of zone A above the tuyeres of the blast furnace softening zone can be calculated as follows:

[0148] ΔVA 总 =VA burden +ΔVA v +ΔVA PCL

[0149] = 1.72% - 0.48% + 3.75%

[0150] =4.99%

[0151] Calculate the volume change rate of blast furnace zone B:

[0152] ΔVB 总 =VB burden +ΔVB v +ΔVB PCL

[0153] = 4.03% - 0.3% + 0.71%

[0154] =4.44%

[0155] (6) Calculation of changes in blast furnace gas utilization rate

[0156] The change in blast furnace gas utilization rate is equal to the sum of the gas utilization rates in zones A and B, denoted by σ. A This represents the effect of the gas volume change rate in area A on the gas utilization rate η. CO Influence coefficient; expressed as σ B This indicates the effect of the gas volume change rate in zone B on the gas utilization rate η. CO The influence coefficient is obtained by calculating the data ΔVA according to step (4). 总 =4.99%, ΔVB 总 =4.44% Empirical data σ was obtained from Table 12. A =0.092, σ B =-0.056, the adjusted total blast furnace gas volume is 7150.2m³. 3 / min, from Table 7, the distribution rate α of blast furnace gas in area A is α00.71, then the change in blast furnace gas utilization rate Δη CO It is expressed as follows:

[0157] Δη CO =σ A ·ΔVA 总 ·α+σ B ·ΔVB 总 ·(1-α)

[0158] = 0.092 × 4.99% × 0.71 + (-0.056) × 4.44% × (1 - 0.71)

[0159] =0.326% -0.072%

[0160] =0.254%

[0161]

[0162]

[0163] Table 12: σ A and σ B With ΔVA 总 and ΔVB 总 Changes in empirical values

[0164] Therefore, it can be estimated that after the above adjustments, the blast furnace gas utilization rate is expected to increase by 0.254%, which is conducive to reducing fuel consumption in the blast furnace.

[0165] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace, characterized in that: Includes the following steps: The lower gas flow space of the blast furnace is divided into two areas, A and B. Area A is the soft melting zone of the blast furnace edge and the central soft melting zone of the blast furnace. Calculate the blast furnace reference gas volume; Based on the blast furnace reference gas volume, calculate the impact of the charging operation on the gas volume space in blast furnace A area, the impact of the charging operation on the gas volume space in blast furnace B area, the impact of the blast wind speed on the gas volume space in blast furnace A area, the impact of the blast wind speed on the gas volume space in blast furnace B area, the impact of oxygen enrichment and pulverized coal volatiles on the gas space changes in blast furnace A area, and the impact of oxygen enrichment and pulverized coal volatiles on the gas space changes in blast furnace B area. The comprehensive change rate of the gas space in blast furnace A area is obtained by summing the values ​​of the influence of fabric placement on the gas volume space in blast furnace A area, the influence of blast wind speed on the gas volume space in blast furnace A area, and the influence of oxygen enrichment and volatile matter of pulverized coal injection on the gas space changes in blast furnace A area. The comprehensive change rate of the gas space in blast furnace B area is obtained by summing the values ​​of the influence of fabric placement on the gas volume space in blast furnace B area, the influence of blast wind speed on the gas volume space in blast furnace B area, and the influence of oxygen enrichment and volatile matter of pulverized coal injection on the gas space changes in blast furnace B area. The change in blast furnace gas utilization rate is calculated based on the comprehensive change rate of gas space in blast furnace A area and the comprehensive change rate of gas space in blast furnace B area.

2. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 1, characterized in that: Calculate the reference gas volume for the blast furnace: Vg=121%·V airr +2×VO2+V vad Where: V air - Volumetric blast of hot air entering the furnace; Vg - Volumetric gas volume of reference coal at the front end of the blast furnace tuyeres; VO2 - Volumetric oxygenation in the reference blast furnace gas; V vad -Volume amount of volatile matter from pulverized coal injection.

3. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 2, characterized in that: Calculate the impact of the charging material on the gas volume space in blast furnace A area, ΔVA. burden The influence of the fabric on the gas volume space in blast furnace B area, ΔVB burden : Wherein, α0 is the distribution coefficient of blast furnace gas in area A; γ S0 - Edge fabric reference load; γ S1 - Adjust the load on the edge fabric; γ C0 -Center fabric reference load; γ C1 - Load after center charge adjustment; λx - Correction coefficient; α1 - Distribution coefficient of blast furnace gas in area A after charge adjustment.

4. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 3, characterized in that: Calculate the influence of blast wind speed on the gas volume space of blast furnace A area, ΔVA. v : Where: ν1 - blast velocity after changes in blast furnace inlet area and inlet volume; ν0 - reference blast velocity; V - reference air volume; ΔV - change in air volume; A - reference inlet area; ΔA - change in inlet area; ΔVAv=β·Δν / ν0 Where: β-wind speed affects the distribution coefficient of the initial gas distribution in zone A at the tuyeres; therefore, the influence of the blast wind speed on the gas volume space in zone B of the blast furnace is ΔVB. V : ΔVBv=(1-β)·Δν / ν0 5. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 4, characterized in that: Calculate the impact of oxygen enrichment and volatile matter from pulverized coal injection on the spatial variation of gas in blast furnace zone A, ΔVA. PCL : DVA PCL =δ·(ΔV vad +2ΔVO2) / Vg Where: δ-ΔVA PCL The allocation coefficients in regions A and B The increase in volatile matter content of pulverized coal is ΔV vad The effect of oxygen enrichment on the spatial variation of gas in blast furnace B area, ΔVB PCL : ΔVB PCL =(1-δ)·(ΔV vad +2ΔVO2) / Vg 6. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 5, characterized in that: Calculate the overall spatial variation rate ΔVA of gas in blast furnace A area respectively. 总 The comprehensive change rate of gas space in blast furnace B area ΔVB 总 : ΔVA 总 =VA burden +ΔVA v +ΔVA PCL ΔVB 总 =VB burden +ΔVB v +ΔVB PCL 7. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 6, characterized in that: Calculate the change in blast furnace gas utilization rate Δη CO : See you later. CO =s A ·DVA 总 ·a+s B ·ΔVB 总 ·(1-a) Where, σ A - The effect of the gas volume change rate in area A on the gas utilization rate η CO Influence coefficient; σ B - The effect of gas volume change rate in Zone B on gas utilization rate η CO The influence coefficient; α-the distribution coefficient of blast furnace gas in area A.

8. The method for calculating gas utilization rate using the spatial distribution and changes of gas in the lower part of a blast furnace according to claim 1, characterized in that: 60-70% of the initial gas is allocated to area A near the blast furnace edge softening zone, and 30-40% of the initial gas is allocated to area B, the central material column area of ​​the blast furnace center softening zone.

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