A fuel ratio control method for coping with fluctuation of blast furnace gas utilization rate

Abstract

The application discloses a method for determining fuel ratio when the utilization rate of blast furnace gas fluctuates, and considers the change characteristics of main operating parameters in actual operation of blast furnace production, can accurately reflect the fuel ratio adjustment amount when the utilization rate of blast furnace gas changes in different states, so as to ensure the stability of silicon content in molten iron and molten iron temperature measurement, and not only can be fully utilized in daily heat system operation of the blast furnace, but also can provide a basis for recovery of the blast furnace when the blast furnace gas flow is abnormal and the utilization rate of the blast furnace gas greatly fluctuates, so as to reduce operation errors and accelerate the recovery rhythm.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of steel metallurgical blast furnace production, and in particular to a fuel ratio control method for dealing with blast furnace gas utilization rate fluctuation. BACKGROUND

[0002] The present application gives a control method for adjusting fuel ratio when blast furnace gas utilization rate fluctuates under working condition by using parameters such as thermal system level, fuel ratio control value and gas utilization rate under blast furnace working condition, according to the reduction principle of main elements such as iron, silicon and manganese in blast furnace, and combining the influence value of fuel ratio when gas utilization rate changes under actual working condition.

[0003] The present application aims to: invent a method for adjusting fuel ratio under blast furnace working condition and gas utilization rate fluctuation value, which can be used in stable blast furnace thermal system operation, and can determine reasonable fuel ratio control value when blast furnace gas utilization rate and furnace condition change greatly, to ensure stable thermal system and smooth blast furnace operation. SUMMARY

[0004] The present application aims to: invent a method for adjusting fuel ratio under blast furnace working condition and gas utilization rate fluctuation value, which can be used in stable blast furnace thermal system operation, and can determine reasonable fuel ratio control value when blast furnace gas utilization rate and furnace condition change greatly, to ensure stable thermal system and smooth blast furnace operation.

[0005] The present application is achieved as follows: a fuel ratio control method for dealing with blast furnace gas utilization rate fluctuation, comprising the following steps: step one: calculating ton iron fuel ratio FR 基准 and average value of blast furnace gas utilization rate ηCO 基准 in the previous 8 hours of the current collection point, ton iron fuel ratio FR 基准 in the previous 8 hours of the current collection point = CR + PCI / (P*Ch)*1000, wherein CR is the average value of coke ratio in the previous 8 hours of the current collection point, with unit of kg / ton, PCI is total coal injection amount in the previous 8 hours of the current collection point, with unit of ton, P is iron amount of each batch, with unit of ton, Ch is total batch number in 8 hours of the current collection point, ηCO 基准 is the average value of blast furnace gas utilization rate in the previous 8 hours of the current collection point, with unit of %; step two: calculating average value of blast furnace gas utilization rate ηCO 近期 in the previous 1 hour of the current collection point, calculating measurement difference value of blast furnace gas utilization rate ΔηCO = ηCO 基准 - ηCO 近期 of each collection point, ηCO 基准 is the average value of blast furnace gas utilization rate in the previous 8 hours of the collection point, and ηCO 近期 is the average value of blast furnace gas utilization rate in the previous 1 hour of the collection point. 基准The average blast furnace gas utilization rate at the same sampling point within the previous hour, in percentage; Step 3: The absolute value of the measurement difference in blast furnace gas utilization rate at the current sampling point is less than 0.3, i.e., |ΔηCO| is less than 0.3, and the current blast furnace fuel ratio control value per ton of iron is FR=FR 基准 When |ΔηCO| is greater than or equal to 0.3, proceed to step four; Step four: The absolute value of the measurement difference of blast furnace gas utilization rate at the current collection point is less than 1, that is, |ΔηCO| is less than 1, and the current blast furnace fuel ratio control value FR = FR benchmark + (ηCO benchmark - ηCO recent) × A × 0.5; When |ΔηCO| at the current collection point is greater than or equal to 1, proceed to step five; Step five: The absolute value of the measurement difference of blast furnace gas utilization rate at the current collection point is less than 2, that is, |ΔηCO| is less than 2, and the current blast furnace fuel ratio control value FR = FR benchmark + (ηCO benchmark - ηCO recent) × A×0.75; When the current sampling point |ΔηCO| is greater than or equal to 2, proceed to step six; Step six: When the absolute value of the measurement difference of the blast furnace gas utilization rate at the current sampling point is less than 3, that is, |ΔηCO| is less than 3, the current blast furnace fuel ratio control value FR = FR benchmark + (ηCO benchmark - ηCO recent) × A×1; When the current sampling point |ΔηCO| is greater than or equal to 3, proceed to step seven; Step seven: When the absolute value of the measurement difference of the blast furnace gas utilization rate at the current sampling point is greater than or equal to 3, that is, |ΔηCO| is greater than or equal to 3, the current blast furnace fuel ratio control value FR = FR benchmark + (ηCO) × A×1; 基准 -ηCO 近期 )×A×1.3; Step 8: Add fuel according to the current blast furnace fuel ratio control value FR to stabilize the blast furnace thermal regime.

[0006] Real-time data collection of coke ratio, hourly pulverized coal injection rate, feeding speed, and blast furnace gas utilization rate under blast furnace operating conditions refers to data collection every 10-60 minutes.

[0007] In step one, the average blast furnace gas utilization rate ηCO in the 8 hours prior to the current time. 基准 The average value of blast furnace gas utilization rate in the 8 hours prior to the current time is taken as a percentage. In step two, the average value of blast furnace gas utilization rate in the 8 hours prior to any sampling point is the arithmetic mean of blast furnace gas utilization rate in the 8 hours prior to that sampling point, taken as a percentage.

[0008] In step two, the average blast furnace gas utilization rate ηCO for the previous hour is... 近期 ηCO is the arithmetic mean of blast furnace gas utilization rate in the hour preceding the current time. 近期 To be with ηCO 基准 For the same data collection point, the unit is %.

[0009] When FR 基准 When A is less than 500 kg / t, A is 5.5; when 500 kg / t ≦ FR基准 <520 kg / t, A is 6, when 520 kg / t ≦ FR 基准 <550 kg / t, A is 6.5, when 550 kg / t ≦ FR 基准 <580 kg / t, A is 7.5, when FR 基准 ≥580 kg / t, A is 10.

[0010] The beneficial effects of the present application are: (1) quantifying the fuel ratio control value after the fluctuation of the blast furnace gas utilization rate; (2) determining the fuel ratio adjustment amount when the furnace condition fluctuates and the gas utilization rate changes greatly, stabilizing the blast furnace heat regime, and ensuring the quality of molten iron. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present application will be further described below in conjunction with the drawings.

[0012] Figure 1 is a graph of the fuel ratio adjustment amount when the gas utilization rate fluctuates by 1% under different base fuel ratios of the present application.

[0013] In the graph, the X-axis is the fuel ratio per ton of iron (unit: kg / t), and the Y-axis is the fuel ratio adjustment amount corresponding to a 1% change in the gas utilization rate. DETAILED DESCRIPTION

[0014] The change in blast furnace gas utilization rate is one of the important evaluation bases for reflecting the change in the blast furnace heat regime. The high or low blast furnace gas utilization rate reflects the utilization efficiency of the carbon combustion heat value in the blast furnace, and has a greater impact on the blast furnace heat regime. A large and short-term fluctuation in the gas utilization rate often causes a large change in the blast furnace heat regime, affecting the quality of molten iron. When the gas utilization rate changes greatly in the daily production operation of the blast furnace, the fuel ratio of the blast furnace needs to be adjusted in a timely manner to stabilize the blast furnace heat regime, ensure the stable operation of the blast furnace, and ensure the quality of molten iron, which has a positive effect on the operation of the blast furnace.

[0015] By studying the impact of the fluctuation of the blast furnace gas utilization rate on the blast furnace heat regime, exploring and quantifying the method for stabilizing the blast furnace heat regime in response to the fluctuation of the gas utilization rate in production, using the Rist operating line and combining the actual production situation to obtain relevant fuel ratio control data, the reasonable adjustment amount of the fuel ratio when the gas utilization rate fluctuates to different intervals is given, and the data analysis method and actual production are used for correction, and finally the control method of the fuel ratio when the gas utilization rate fluctuates under the working condition is formed.

[0016] Currently, the control method of fuel ratio when blast furnace gas utilization rate fluctuates is mainly based on experience, and there is no specific method and unified standard. For example, when the blast furnace gas utilization rate decreases by 1%, the adjustment amount of fuel ratio of most enterprises is 4-6 kg / t, and the adjustment amount of fuel ratio of some enterprises is 6-8 kg / t. However, in actual production, the influence of the fluctuation of blast furnace gas utilization rate in different fuel ratio ranges on the heat system is different, and the adjustment value of the combustion ratio corresponding to the fluctuation of 1% of the blast furnace gas utilization rate under different gas utilization rates is different, as shown in the following table. Figure 1

[0017] As can be seen from Figure 1 , the higher the basic fuel ratio of the blast furnace, the lower the fuel ratio before the fluctuation of the gas utilization rate, and the less the corresponding adjustment of the fuel ratio when the gas utilization rate fluctuates by 1%. This is corresponding to the fact that the lower the fuel ratio, the lower the demand for carbon in the smelting process. In actual production, the traditional method has poor usability and accuracy, and the blast furnace heat system cannot be effectively controlled when the basic fuel ratio fluctuates in different intervals, which is the main problem to be solved by the present application.

[0018] Under the actual smelting conditions of the blast furnace, the heat system of the blast furnace is realized by the fuel ratio per ton of iron, and the fuel ratio can be calculated by the coke ratio, the hourly coal quantity and the hourly coal injection quantity.

[0019] The technical problem to be solved by the present application is: how to obtain the control value calculation formula of the fuel ratio in different blast furnace gas utilization rate change intervals according to the heat balance principle and the actual production situation by the blast furnace gas utilization rate change value and the corresponding basic fuel ratio per ton of iron, and finally determine the control value of the fuel ratio per ton of iron after the fluctuation of the blast furnace gas utilization rate.

[0020] 1. The technical solution adopted by the present application is: a fuel ratio control method for responding to the fluctuation of the blast furnace gas utilization rate. After the blast furnace is operated, the coke ratio, the hourly coal injection quantity, the batch quantity of iron, the batch number of material, the blast furnace gas utilization rate under the working condition of the blast furnace are collected in real time, and after the blast furnace is operated for 8 hours, the fuel ratio control for responding to the fluctuation of the blast furnace gas utilization rate is carried out according to the following steps.

[0021] Step one, calculate the fuel ratio per ton of iron FR 基准 and the average value of the blast furnace gas utilization rate ηCO 基准 in the previous 8 hours of the current collection point, the fuel ratio per ton of iron FR 基准 in the previous 8 hours of the current collection point = CR + PCI / (P*Ch)*1000, wherein CR is the average value of the coke ratio in the previous 8 hours of the current collection point, the unit is kg / ton, PCI is the total amount of coal injection in the previous 8 hours of the current collection point, the unit is ton, P is the batch quantity of iron, the unit is ton, Ch is the total batch number of material in the previous 8 hours of the current collection point; ηCO 基准 is the average value of the blast furnace gas utilization rate in the previous 8 hours of the current collection point, the unit is %.​

[0022] Step two, calculate the average value of the blast furnace gas utilization rate in the previous 1 hour of the current collection point ηCO 近期 , calculate the measurement difference of the blast furnace gas utilization rate of each collection point ΔηCO = ηCO 基准 - ηCO 近期 , ηCO 基准 is the average value of the blast furnace gas utilization rate in the previous 8 hours of the collection point, and ηCO 近期 is the average value of the blast furnace gas utilization rate in the previous 1 hour of the same collection point as ηCO 基准 , with the unit of %.

[0023] Step three, the absolute value of the measurement difference of the blast furnace gas utilization rate of the current collection point is less than 0.3, that is, |ΔηCO| is less than 0.3, and the current ton iron fuel ratio control value of the blast furnace FR = FR 基准 When |ΔηCO| is greater than or equal to 0.3, go to step four.

[0024] Step four, the absolute value of the measurement difference of the blast furnace gas utilization rate of the current collection point is less than 1, that is, |ΔηCO| is less than 1, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 0.5; When the current collection point |ΔηCO| is greater than or equal to 1, go to step five.

[0025] Step five, the absolute value of the measurement difference of the blast furnace gas utilization rate of the current collection point is less than 2, that is, |ΔηCO| is less than 2, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 0.75; When the current collection point |ΔηCO| is greater than or equal to 2, go to step six.

[0026] Step six, the absolute value of the measurement difference of the blast furnace gas utilization rate of the current collection point is less than 3, that is, |ΔηCO| is less than 3, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 1; When the current collection point |ΔηCO| is greater than or equal to 3, go to step seven.

[0027] Step seven, the absolute value of the measurement difference of the blast furnace gas utilization rate of the current collection point is greater than or equal to 3, that is, |ΔηCO| is greater than or equal to 3, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO 基准 - ηCO 近期 ) × A × 1.3.

[0028] Step eight, input fuel according to the current ton iron fuel ratio control value FR of the blast furnace, and stabilize the heat system of the blast furnace.

[0029] 2. Collecting the coke ratio, the coal injection rate per hour, the discharge speed and the blast furnace gas utilization rate under the blast furnace working condition in real time, i.e. collecting once every 10-60 minutes.

[0030] 3. In step one, the average value ηCO 基准 is the arithmetic average value of the blast furnace gas utilization rate within 8 hours before the current time, and the unit is %. In step two, the average value ηCO

[0031] 4. In step two, the average value ηCO 近期 is the arithmetic average value of the blast furnace gas utilization rate within 1 hour before the current time, and the unit is %. ηCO 近期 is the average value of the blast furnace gas utilization rate within 8 hours before the current time, and the unit is %. 基准 is the same as ηCO

[0032] 5. When FR 基准 < 500 kg / t, A is 5.5, when 500 kg / t ≦ FR 基准 < 520 kg / t, A is 6, when 520 kg / t ≦ FR 基准 < 550 kg / t, A is 6.5, when 550 kg / t ≦ FR 基准 < 580 kg / t, A is 7.5, when FR 基准 ≥ 580 kg / t, A is 10.

[0033] The specific embodiments of the present application are further illustrated by the following examples, but the specific embodiments of the present application are not limited to the following examples.

[0034] First, the reference example is introduced, which is the control method for stabilizing the blast furnace temperature after the fluctuation of the blast furnace gas utilization rate according to the traditional calculation method, i.e. the traditional experience.

[0035] Reference Example

[0036] It is known that under three different working conditions, the blast furnace gas utilization rate is adjusted by 1% according to the traditional method, and the fuel ratio is adjusted by 6 kg / t. Among them, working condition one is normal furnace condition, and working conditions two and three are furnace conditions in which the blast furnace gas utilization rate fluctuates greatly. The blast furnace temperature level under different working conditions after the traditional method is adopted is shown in Table 1.

[0037] Table 1: Results of the reference example

[0038]

[0039] The fuel ratio control value FR after the change of the gas utilization rate (working condition one) = 495 + (51-50) x 6 = 500.4 kg / t.

[0040] The fuel ratio control value FR after the change of the gas utilization rate (working condition two) = 503 + (49.2-47.6) x 6 = 512.6 kg / t.

[0041] The fuel ratio control value FR after the change of the gas utilization rate (working condition three) = 522 + (47.3-43.8) x 6 = 543 kg / t.

[0042] From the comparison of the three working conditions, when the basic fuel ratio is low and the fluctuation of the blast furnace gas utilization rate is small, the furnace temperature control is prone to be high when adjusted according to the traditional method, but when the basic fuel ratio is high and the fluctuation of the blast furnace gas utilization rate is large, the furnace temperature control is prone to be low when adjusted according to the traditional method.

[0043] The following introduces an embodiment of the present application, and the furnace temperature control method when the blast furnace gas utilization rate fluctuates is mainly based on the method of the present application.

[0044] From the comparison of the three working conditions, when the basic fuel ratio is low and the fluctuation of the blast furnace gas utilization rate is small, the furnace temperature control is prone to be high when adjusted according to the traditional method, but when the basic fuel ratio is high and the fluctuation of the blast furnace gas utilization rate is large, the furnace temperature control is prone to be low when adjusted according to the traditional method. Figure 1 It can be seen from the comparison of the three working conditions that the higher the basic fuel ratio of the blast furnace, the lower the fuel ratio before the fluctuation of the gas utilization rate, and the smaller the adjusted fuel ratio corresponding to the fluctuation of 1% of the gas utilization rate, which corresponds to the lower the fuel ratio, the lower the demand for carbon in the smelting process. In actual production, the traditional method has poor usability and accuracy, and the basic fuel ratio cannot be effectively controlled in different intervals. The main problem to be solved by the present application is the blast furnace heat regime.

[0045] Implementation case

[0046] A fuel ratio control method for responding to the fluctuation of the blast furnace gas utilization rate, after the blast furnace is operated, the coke ratio, the hourly coal injection amount, the batch iron amount, the batch number, and the blast furnace gas utilization rate under the working condition of the blast furnace are collected every 10 minutes in real time, and after the blast furnace is operated for 8 hours, the fuel ratio control for responding to the fluctuation of the blast furnace gas utilization rate is performed according to the following steps.

[0047] Step one, calculating the ton iron fuel ratio FR of the 8 hours before the current collection point 基准 and the average value ηCO 基准 of the blast furnace gas utilization rate in the 8 hours before the current collection point, the ton iron fuel ratio FR of the 8 hours before the current collection point 基准 = CR + PCI / (P x Ch) x 1000, wherein CR is the average value of the coke ratio in the 8 hours before the current collection point, with the unit of kg / t, PCI is the total amount of coal injection in the 8 hours before the current collection point, with the unit of ton, P is the batch iron amount, with the unit of ton, and Ch is the total batch number of the 8 hours before the current collection point; ηCO 基准ηCO recent is the average value of blast furnace gas utilization rate in the past 8 hours of the current collection point, unit: %.

[0048] Step two, calculate the average value of blast furnace gas utilization rate in the past 1 hour of the current collection point ηCO 近期 , calculate the measurement difference of blast furnace gas utilization rate of each collection point ΔηCO = ηCO 基准 -ηCO 近期 , ηCO 基准 is the average value of blast furnace gas utilization rate in the past 8 hours of the collection point, ηCO 近期 is the average value of blast furnace gas utilization rate in the past 1 hour of the same collection point as ηCO 基准 , unit: %.

[0049] Step three, the absolute value of the measurement difference of blast furnace gas utilization rate of the current collection point is less than 0.3, that is, |ΔηCO| is less than 0.3, and the current ton iron fuel ratio control value of the blast furnace FR = FR 基准 , when |ΔηCO| is greater than or equal to 0.3, enter step four.

[0050] Step four, the absolute value of the measurement difference of blast furnace gas utilization rate of the current collection point is less than 1, that is, |ΔηCO| is less than 1, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 0.5; when |ΔηCO| of the current collection point is greater than or equal to 1, enter step five.

[0051] Step five, the absolute value of the measurement difference of blast furnace gas utilization rate of the current collection point is less than 2, that is, |ΔηCO| is less than 2, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 0.75; when |ΔηCO| of the current collection point is greater than or equal to 2, enter step six.

[0052] Step six, the absolute value of the measurement difference of blast furnace gas utilization rate of the current collection point is less than 3, that is, |ΔηCO| is less than 3, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO reference - ηCO recent) × A × 1; when |ΔηCO| of the current collection point is greater than or equal to 3, enter step seven.

[0053] Step seven, the absolute value of the measurement difference of blast furnace gas utilization rate of the current collection point is greater than or equal to 3, that is, |ΔηCO| is greater than or equal to 3, and the current ton iron fuel ratio control value of the blast furnace FR = FR reference + (ηCO 基准 -ηCO 近期 ) × A × 1.3.

[0054] Step eight, input fuel according to the current ton iron fuel ratio control value FR of the blast furnace, and stabilize the heat system of the blast furnace.

[0055] 2. Collecting the coke ratio, the coal injection rate per hour, the discharging speed and the blast furnace gas utilization rate under the blast furnace working condition in real time, i.e. collecting once every 10-60 minutes.

[0056] 3. In step one, the average value ηCO of the blast furnace gas utilization rate in the last 8 hours before the current time 基准 is the arithmetic average value of the blast furnace gas utilization rate in the last 8 hours before the current time, and the unit is %.

[0057] 4. In step two, the average value ηCO of the blast furnace gas utilization rate in the last 1 hour before the current time 近期 is the arithmetic average value of the blast furnace gas utilization rate in the last 1 hour before the current time, and ηCO 近期 is the average value of the blast furnace gas utilization rate in the last 1 hour before the current time, and the unit is %. 基准 is the average value of the blast furnace gas utilization rate in the last 1 hour before the current time, and the unit is %.

[0058] 5. When FR 基准 < 500 kg / t, A is 5.5, when 500 kg / t ≦ FR 基准 < 520 kg / t, A is 6, when 520 kg / t ≦ FR 基准 < 550 kg / t, A is 6.5, when 550 kg / t ≦ FR 基准 < 580 kg / t, A is 7.5, when FR 基准 ≥ 580 kg / t, A is 10.

[0059] Table 2 Corresponding relationship between the fuel ratio conversion coefficient and the reference fuel ratio

[0060] FR reference ＜500 500～520 520～550 550～580 ＞580 5.5 6 6.5 7.5 10

[0061] Under three different working conditions, according to the method adjustment of the present application, when the blast furnace gas utilization rate fluctuates by 1%, the control amount of the fuel ratio corresponding to the instant value of the fluctuation of the blast furnace gas utilization rate under the working condition is calculated according to the steps in the technical solution of the present application, so as to realize the stability of the heat system, and the adjustment results of the traditional method in the reference implementation case are compared. The specific results are shown in Table 3.

[0062] Table 3 Implementation case results

[0063]

[0064] Working condition one: A value 5.5, B value 0.5; working condition two: A value 6, B value 0.75; working condition three: A value 6.5, B value 1.3.

[0065] The fuel ratio control value FR after the change of the coal gas utilization rate (working condition one) = 496 + (50.9-50.2) * 5.5 * 0.5 = 497.9 kg / t.

[0066] The fuel ratio control value FR after the change of the coal gas utilization rate (working condition two) = 502 + (49.3-47.7) * 6 * 0.75 = 509.2 kg / t.

[0067] The fuel ratio control value FR after the change of the coal gas utilization rate (working condition three) = 524 + (47.2-43.1) * 6.5 * 1.3 = 558.6 kg / t.

[0068] Compared with the traditional control method, the traditional control method has poor control effect on the furnace temperature when the blast furnace gas utilization rate fluctuates greatly, and when the blast furnace gas utilization rate decreases from 47.3% to 43.8%, the furnace temperature decreases by 0.27%, while when the blast furnace gas utilization rate decreases from 47.2% to 43.1% using the control method of the present application, the furnace temperature basically remains stable.

[0069] It can be seen from the comparison of the results that the traditional method has poor control effect on the furnace temperature when the blast furnace gas utilization rate fluctuates greatly, while the control effect of the present application on the furnace temperature is better, and the present application is more practical compared with the traditional method.

[0070] The above is only a specific embodiment of the present application, but the structural features of the scope of protection of the present application are not limited thereto, any changes or modifications made by those skilled in the art within the scope of the present application are covered by the patent scope of the present application.

Claims

1. A method of fuel ratio control to cope with fluctuations in blast furnace gas utilization, characterized by: The method comprises the following steps: Step 1: Calculate the FR ratio of tonne iron fuel at the current sampling point for the previous 8 hours. 基准 And the average value of blast furnace gas utilization rate ηCO in the previous 8 hours at the current sampling point 基准 The current sampling point's iron ore fuel ratio in the previous 8 hours was higher than that of FR. 基准 =CR + PCI / (P × Ch) × 1000, where CR is the average coke ratio of the current sampling point in the previous 8 hours, in kg / ton; PCI is the total amount of pulverized coal injected in the previous 8 hours, in tons; P is the amount of iron per batch, in tons; and Ch is the total number of batches discharged from the current sampling point in the previous 8 hours; ηCO 基准 This represents the average blast furnace gas utilization rate at the current sampling point over the previous 8 hours, expressed as a percentage. Step two: calculate the average value of the blast furnace gas utilization rate of the previous 1 hour of the current collection point ηCO 近期 , calculate the measurement difference of the blast furnace gas utilization rate of each collection point ΔηCO = ηCO 基准 - ηCO 近期 , ηCO 基准 is the average value of the blast furnace gas utilization rate within the previous 8 hours of the collection point, and ηCO 近期 is the average value of the blast furnace gas utilization rate within the previous 1 hour of the same collection point as ηCO 基准 , unit: %; Step three: the absolute value of the measurement difference of the current collection point blast furnace gas utilization rate is less than 0.3, that is, |ΔηCO| is less than 0.3, and the current ton of iron fuel ratio control value of the blast furnace is FR=FR 基准 When |ΔηCO| is greater than or equal to 0.3, step four is entered. Step four: the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is less than 1, i.e. |ΔηCO| is less than 1, the blast furnace current ton iron fuel ratio control value FR=FRbase+(ηCObase-ηCOrecent)×A×0.5; when the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is greater than or equal to 1, step five is entered; Step five: the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is less than 2, i.e. |ΔηCO| is less than 2, the blast furnace current ton iron fuel ratio control value FR=FRbase+(ηCObase-ηCOrecent)×A×0.75; when the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is greater than or equal to 2, step six is entered; Step six: the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is less than 3, i.e. |ΔηCO| is less than 3, the blast furnace current ton iron fuel ratio control value FR=FRbase+(ηCObase-ηCOrecent)×A×1; when the absolute value of the measurement difference of the blast furnace gas utilization rate at the current collection point is greater than or equal to 3, step seven is entered; Step seven: the absolute value of the measurement difference of the current collection point blast furnace gas utilization rate is greater than or equal to 3, that is, |ΔηCO| is greater than or equal to 3, the current ton of iron fuel ratio control value of the blast furnace is FR=FRbase+(ηCO 基准 -ηCO 近期 )×A×1.3; Step eight: fuel is input according to the blast furnace current ton iron fuel ratio control value FR, and the blast furnace heat regime is stabilized.

2. The fuel ratio control method for coping with fluctuation in utilization rate of blast furnace gas according to claim 1, characterized by: The coke ratio, the coal injection amount per hour, the discharging speed and the blast furnace gas utilization rate under the blast furnace working condition are collected in real time, which means that the collection is performed every 10-60 minutes.

3. The fuel ratio control method for coping with fluctuation in utilization rate of blast furnace gas according to claim 1, characterized by: ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 基准 ηco 4. The fuel ratio control method for coping with fluctuation in utilization rate of blast furnace gas according to claim 1, characterized by: In step two, the average blast furnace gas utilization rate ηCO for the previous hour is... 近期 ηCO is the arithmetic mean of blast furnace gas utilization rate in the hour preceding the current time. 近期 To be with ηCO 基准 For the same data collection point, the unit is %.

5. The fuel ratio control method for coping with fluctuation in utilization rate of blast furnace gas according to claim 1, characterized by: When FR 基准 When A is less than 500 kg / t, A is 5.5; when 500 kg / t ≦ FR 基准 When A is less than 520 kg / t, A is 6; when 520 kg / t ≦ FR 基准 When A is less than 550 kg / t, A is 6.5; when 550 kg / t ≦ FR 基准 When FR is <580kg / t, A is 7.

5. 基准 When the value is ≥580kg / t, A is 10.

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