Method for adjusting blast furnace tuyere air supply area according to seasonal atmospheric humidity change

Abstract

The invention relates to the field of ferrous metallurgy, in particular to a method for adjusting the air supply area of a blast furnace tuyere according to seasonal atmospheric humidity change. The air volume needing to be supplemented for blast furnace hearth heat balance change caused by humidity change is calculated; and calculating the blast-furnace tuyere air supply area variation. The method has the advantages that the air supply area of the blast-furnace tuyere can be more accurately adjusted by calculating the influence of the moisture on the heat of the blast-furnace hearth and the air volume change requirement caused by the influence, so that the blast-furnace air volume is matched with the heat change of the hearth; reasonable adjustment of the air supply area of the tuyere is beneficial for guaranteeing stability of a tuyere rotation area, the stable tuyere rotation area can reduce turbulence of airflow in a hearth, and the utilization rate of coal gas is increased; and through quantitative calculation, the blindness can be avoided, so that unnecessary energy consumption is reduced as much as possible on the premise that the blast furnace meets the production requirements, and the energy cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy, and more particularly to a method for adjusting the air supply area of ​​a blast furnace tuyeres according to seasonal changes in atmospheric humidity. Background Technology

[0002] With changes in atmospheric humidity, the blast density and humidity change regularly. The impact of increased humidity on the blast furnace mainly includes the heat absorption of moisture decomposition and changes in the amount of gas in the hearth and the heat it carries. These two changes reflect the changes in the heat balance of the hearth caused by changes in blast humidity, thus affecting the blast furnace feed air volume and gas flow distribution. It can be said that seasonal changes in atmospheric humidity have a significant impact on various economic and technical indicators of the blast furnace.

[0003] To overcome the adverse effects of atmospheric humidity changes on blast furnaces, without resorting to forced blast dehumidification, the upper and lower operating procedures of the blast furnace must be appropriately adjusted to ensure a reasonable distribution of gas flow and stable heat. Adjusting the blast area is usually an important means of matching the blast volume entering the blast furnace due to seasonal climate changes, and it is the most important lower-level adjustment to ensure the stability of the tuyere swirling zone. Adjusting the tuyere according to seasonal atmospheric humidity changes is essential. In the past, adjusting the tuyere blast area was largely based on experience, without a quantitative standard to rely on. Therefore, it is urgent to develop a method that can adjust the blast furnace tuyere blast area according to seasonal atmospheric humidity changes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for adjusting the air supply area of ​​the blast furnace tuyeres according to seasonal changes in atmospheric humidity, which helps to maintain the stability of the blast furnace hearth heat and the tuyeres vortex zone, and avoids fluctuations in the smooth operation of the blast furnace caused by seasonal changes in atmospheric humidity.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for adjusting the air supply area of ​​a blast furnace tuyeres according to seasonal changes in atmospheric humidity includes:

[0007] Calculate the effect of moisture on the heat of the blast furnace hearth;

[0008] Calculate the amount of air needed to compensate for changes in the heat balance of the blast furnace hearth caused by humidity variations.

[0009] Calculate the change in the air supply area of ​​the blast furnace tuyeres.

[0010] Calculate the effect of moisture on the heat of the blast furnace hearth, starting from the tuyeres area (1m). 3 Heat balance calculation of the furnace hearth The calculation formula is as follows:

[0011] ①

[0012] In formula ①: This represents the physical heat carried in by each kilogram of coke entering the tuyeres, usually considered based on the specific enthalpy of coke at 1500℃. =4.18 ×(540~550) kJ / kg; The heat consumed in the decomposition of coal powder per kilogram of carbon is usually expressed as... =4.18×300kJ / kg, calculated according to the conversion of anthracite; This indicates the specific heat capacity of the blower air at the hot air temperature, expressed in kJ / (m³). 3 ·℃); The value indicates the hot air temperature, in °C; f indicates the blower air humidity. This indicates the proportion of coke carbon in the total carbon content of combustion before the vent; C b m This indicates the proportion of pulverized coal carbon in the total carbon content of combustion before the tuyeres; (O2) b Indicates 1m 3 The oxygen content of the blower air, of which (O2) b =0.21+0.29f+η, where η represents the oxygen enrichment rate, in percentages (%).

[0013] The effect of moisture change on the heat of the blast furnace hearth, ∆Q, can be obtained from formula ①, as follows:

[0014] ②

[0015] In formula ②, This represents the absolute humidity difference, expressed in g / Nm³. 3 .

[0016] The formula for calculating the additional air volume required to offset the change in heat balance in the blast furnace hearth due to humidity changes is as follows:

[0017] ③

[0018] In formula ③, This indicates the amount of air needed to compensate for changes in the heat balance of the blast furnace hearth due to humidity variations, expressed in m³. 3 ; express The specific heat capacity of the furnace hearth gas is expressed in kJ / (m³). 3 ·℃).

[0019] The formula for calculating the change in the air supply area of ​​the blast furnace tuyeres is as follows:

[0020] ④

[0021] In formula ④, This indicates the change in the air supply area of ​​the blast furnace tuyeres; This indicates the suitable standard wind speed for a blast furnace, expressed in m / s. This indicates the current blast furnace air volume, in meters (m³). 3 / min;

[0022] From formulas ② and ③, the following formula is derived:

[0023] ⑤.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. By calculating the impact of moisture on the heat of the blast furnace hearth and the resulting change in air volume requirements, the air supply area of ​​the blast furnace tuyeres can be adjusted more precisely, so that the air volume entering the blast furnace matches the heat balance of the hearth, thereby optimizing the gas flow distribution and improving the operating efficiency of the blast furnace.

[0026] 2. Reasonable adjustment of the tuyere air supply area helps to ensure the stability of the tuyere swirling zone, which is crucial for the normal operation of the blast furnace. A stable tuyere swirling zone can reduce the turbulence of airflow in the hearth, improve the utilization rate of gas, and thus improve the production efficiency of the blast furnace.

[0027] 3. In the past, empirical adjustments to the tuyeres' air supply area may have resulted in insufficient or excessive air supply, leading to energy waste. However, this invention, through quantitative calculations, can avoid this blind approach, enabling the blast furnace to minimize unnecessary energy consumption and reduce energy costs while meeting production needs. Detailed Implementation

[0028] The present invention will now be described in detail, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0029] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0030] Example 1

[0031] Table 1 shows the annual atmospheric humidity in the area where a 4038m³ blast furnace is located. The summer blast volume is 6600 m³. 3 / min, oxygen enrichment rate 5%, suitable standard wind speed 245-255 m / s; based on specific enthalpy at 1500℃ The value is 4.18 × (540~550) kJ / kg; The value is taken as 4.18 × 300 kJ / kg; the hot air temperature is 1200℃, and the specific heat capacity of the blower air at 1200℃ is 1.421 kJ / (m³). 3 ·℃), The value is 0.612 kg / kg, Cb m The value is 0.388 kg / kg.

[0032] Table 1 is a statistical table of atmospheric humidity for the entire year in the region.

[0033]

[0034] A method for adjusting the air supply area of ​​a blast furnace tuyeres based on seasonal changes in atmospheric humidity includes the following:

[0035] S1, Calculate the humidity changes in summer and winter (1m) 3 The effect of blast furnace air volume on the heat of the blast furnace hearth, ∆Q, is given by the following formula:

[0036]

[0037] =-(4.18×2340+0.612×4.18×550-0.388×4.18×300)×0.31×(18.54-1.55)×10 -3 +4.18×2580×(18.54-1.55)10 -3 =126.9KJ.

[0038] S2, Calculate 1m 3 The amount of air that needs to be added to the blower The formula is as follows:

[0039]

[0040] S3. Calculate the change in blast furnace tuyeres area in summer relative to winter. The formula is as follows:

[0041] 。

[0042] This means that the air supply area needs to be increased by 0.0325m² in summer compared to winter. 2 .

[0043] This invention, by calculating the impact of moisture on the heat of the blast furnace hearth and the resulting changes in air volume requirements, enables more precise adjustment of the blast furnace tuyere air supply area. This ensures that the blast furnace air volume is matched with the heat balance changes in the hearth, thereby optimizing the gas flow distribution and improving blast furnace operating efficiency. Reasonable adjustment of the tuyere air supply area helps ensure the stability of the tuyere swirl zone, which is crucial for the normal operation of the blast furnace. A stable tuyere swirl zone reduces airflow turbulence within the hearth, improves gas utilization, and ultimately enhances blast furnace production efficiency. Previous empirical adjustments to the tuyere air supply area may have resulted in insufficient or excessive air supply, leading to energy waste. This invention, through quantitative calculation, avoids this blind approach, enabling the blast furnace to minimize unnecessary energy consumption and reduce energy costs while meeting production needs.

Claims

1. A method for adjusting blast furnace tuyere blast area according to seasonal atmospheric humidity changes, characterized in that, It comprises: calculating the influence of moisture on the heat of blast furnace hearth; calculating the air volume needed to be supplemented due to the change of moisture leading to the change of heat balance of blast furnace hearth; calculating the change of blast furnace tuyere air supply area.

2. The method of claim 1, wherein the method is characterized by, The calculation of the effect of moisture on the heat of the blast furnace hearth is based on the heat balance calculation of the tuyere zone 1 m 3 The heat of the hearth derived from the heat balance calculation of the blast The calculation formula is as follows: ① In formula (1), represents the physical heat brought into the tuyere zone per kg of coke, usually considered according to the specific enthalpy of coke at 1500℃, wherein, = 4.18 × (540~550) kJ / kg; represents the heat consumption for decomposition of coal powder per kg of carbon, usually taken as = 4.18 × 300 kJ / kg, according to the reduction of anthracite; represents the specific heat capacity of hot blast at hot blast temperature, with the unit of kJ / (m 3 ·℃); represents the hot blast temperature, with the unit of ℃; f represents the humidity of blast; represents the proportion of coke carbon in the amount of carbon combusted before the tuyere; C b m represents the proportion of coal powder carbon in the amount of carbon combusted before the tuyere; (O2) b represents the oxygen content of 1 m 3 of blast, wherein, (O2) b = 0.21 + 0.29f + η, η represents the oxygen enrichment rate, with the unit of %. The influence of moisture change on the heat of blast furnace hearth is obtained by formula ①, and the formula is as follows: ② In formula (2), represents the absolute humidity difference, in g / Nm 3 .

3. The method of claim 1, wherein the method is characterized by, The air volume needed to be supplemented due to the change of moisture leading to the change of heat balance of blast furnace hearth is calculated, and the formula is as follows: ③ In formula 3, represents the air volume required to compensate for the change in heat balance of the blast furnace hearth caused by the change in humidity, in m 3 ; represents the specific heat capacity of the hearth gas at the time, in kJ / (m3·℃).

4. The method of claim 1, wherein the method is characterized by, The change of blast furnace tuyere air supply area is calculated, and the formula is as follows: ④ In formula (4), represents the change amount of the blast furnace tuyere blast area; represents the appropriate standard blast speed of the blast furnace, and the unit is m / s; represents the current blast furnace blast volume, and the unit is m 3 / min; According to formula ② and formula ③, the following formula is derived: ⑤。

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