Method for calculating tuyere blowing gas thermal lag time of hydrogen-rich carbon circulating oxygen blast furnace

Abstract

The invention discloses a method for calculating the hot lag time of tuyere blowing coal gas of a hydrogen-carbon-rich circulating oxygen blast furnace, which comprises the following steps of: calculating the hot lag time of tuyere blowing high-temperature upgraded coal gas according to the blank volume of the hydrogen-carbon-rich circulating oxygen blast furnace, the time required by each batch of materials, the volume between the lower part of a furnace body and the central line of a tuyere and a smelting period; and according to the heat lag time and the smelting period of the tuyere injection decarburized gas, the adjustment time of the tuyere injection decarburized gas is confirmed, and finally an operation basis is provided for furnace heat adjustment of the hydrogen-rich carbon circulation oxygen blast furnace. According to the method, the problem that the furnace heat adjusting time is difficult to determine due to the heat hysteresis of the tuyere blowing gas of the hydrogen-rich carbon circulating oxygen blast furnace is solved.

Description

Technical Field

[0001] The invention relates to a hydrogen-rich carbon cycle oxygen blast furnace technology, and more specifically to a method for calculating the thermal lag time of coal gas injected into a tuyere of a hydrogen-rich carbon cycle oxygen blast furnace. Background Art

[0002] The hydrogen-rich carbon circulating oxygen blast furnace process is based on the traditional blast furnace process. It reduces iron ore through full oxygen smelting and injection of high-temperature upgraded circulating coal gas, and utilizes hydrogen to replace carbon as a reducing agent in the blast furnace ironmaking process to the maximum extent. The hydrogen in the coal gas during the coal gas circulation process is recycled in the blast furnace, solving the problem of decreased hydrogen utilization rate after the blast furnace uses a large amount of hydrogen-rich substances, thereby reducing the consumption of fossil energy in the blast furnace process and achieving the goal of further reducing carbon emissions from the blast furnace.

[0003] The thermal reaction of coal gas injected into the blast furnace has a certain hysteresis. In the actual production process, operators usually adjust the thermal system such as coal gas volume or coke load by estimating a thermal lag time value. However, the estimated value is not accurate. If the deviation is too large, it will have an adverse effect on the thermal balance of the blast furnace, which may cause furnace temperature fluctuations or even abnormal furnace conditions. How to combine the actual production parameters of the hydrogen-rich carbon cycle oxygen blast furnace and determine the thermal lag time of coal gas injected into the blast furnace tuyere through theoretical calculation is of great significance to the thermal balance of the hydrogen-rich carbon cycle oxygen blast furnace.

[0004] In existing patent applications, such as Chinese patent application No. 202310208023.0, a method and system for determining the operating window of a hydrogen-rich blast furnace are disclosed, and a method and system for determining the operating window of a hydrogen-rich blast furnace are introduced. The injection conditions are used as input, and a thermal calculation model of the hydrogen-rich blast furnace is used to calculate multiple target indicators to obtain a data parameter set. Then, the injection conditions corresponding to the target indicators are selected from the data parameter set when the target indicators are set values ​​to obtain a set of injection conditions corresponding to each target indicator. Finally, a two-dimensional coordinate system is constructed with the hydrogen-rich medium injection amount and the oxygen enrichment rate as coordinate axes, and multiple data points are determined in the two-dimensional coordinate system. All data points are connected to obtain the boundary of each target indicator, and the boundaries of all target indicators are intersected to form an operating window of the hydrogen-rich blast furnace with the theoretical combustion temperature-coke ratio-ton iron carbon consumption-CO2 emissions as boundaries, thereby providing technical guidance for hydrogen-rich injection in blast furnaces. For example, Chinese patent application No. 201580015653.X discloses an operating method of an oxygen blast furnace, which introduces an operating method of an oxygen blast furnace that can achieve low temperature of the combustion area in front of the tuyere while reducing CO2 emissions compared with the past. In the operating method of an oxygen blast furnace that at least pure oxygen is blown into the tuyere and blast furnace gas with less nitrogen is generated from the furnace top, a tuyere-blown gas having a sum of the volume percentages of hydrocarbons and hydrogen of more than 50% is blown into the tuyere together with the blowing of pure oxygen from the tuyere, thereby reducing the temperature of the combustion area in front of the tuyere. For example, Chinese patent application No. 202111468019.5 discloses a blowing control device and method for low-carbon smelting in a blast furnace, and introduces a blowing control device and method for low-carbon smelting in a blast furnace, including a blast furnace tuyere for introducing oxygen-rich or pure oxygen to form a tuyere vortex zone; a plurality of temperature-adjusting blowing ports are evenly arranged along the circumference of the blast furnace, and the temperature near the tuyere vortex zone is used to cause a thermal cracking reaction of the hydrocarbon-containing component injection material to form a hydrocarbon thermal cracking endothermic zone, and the gaseous products produced by the thermal cracking reaction of the hydrocarbon-containing component injection material increase the blast furnace gas volume, while carrying excess heat from the lower high-temperature zone to the upper part of the blast furnace, thereby flexibly solving the problem of "hot at the bottom and cold at the top" in oxygen-rich blast furnaces or oxygen blast furnaces. For example, Chinese patent application No. 202210000307.6 discloses an ironmaking method using blast furnace to inject Ouye furnace gas, and introduces an ironmaking method using blast furnace to inject Ouye furnace gas, in which the raw materials are distributed in alternating layers to form coke and ore in the furnace, and Ouye furnace decarbonized gas is injected at the blast furnace tuyere through a combined tuyere. The raw materials are weighed under a trough, loaded into the distribution equipment from the top of the blast furnace through a conveyor belt, and added to the blast furnace from the top in batches according to the coke bed layer and the ore layer, with a coal injection amount of 70 to 80 kg / t and a smelting cycle of 6.0 to 8.0 h.

[0005] However, none of the above patented technologies involve the technical analysis and calculation methods related to the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon circulating oxygen blast furnace. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon-cycle oxygen blast furnace, thereby solving the problem that the furnace heat adjustment time is difficult to determine due to the thermal lag of coal gas injected into the tuyere of the hydrogen-rich carbon-cycle oxygen blast furnace.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace:

[0009] According to the billet volume of the hydrogen-rich carbon circulating oxygen blast furnace, the time required for each batch of materials, the volume between the lower part of the furnace body and the center line of the tuyere, and the smelting cycle, the thermal lag time of the high-temperature quality-improving coal gas injected from the tuyere is calculated;

[0010] According to the thermal lag time and smelting cycle of the decarbonized coal gas injected into the tuyere, the adjustment time of the decarbonized coal gas injected into the tuyere is determined, and finally an operating basis is provided for the furnace heat adjustment of the hydrogen-rich carbon circulating oxygen blast furnace.

[0011] Preferably, the method for calculating the thermal lag time of coal gas injected from the tuyere specifically comprises the following steps:

[0012] S1, according to the batch weight and bulk density of sintered ore, pelletized ore, lump ore and coke in the charge of the hydrogen-rich carbon circulating oxygen blast furnace, as well as the batch iron of each batch, calculate the volume of each batch of materials and the charge volume per unit molten iron output;

[0013] S2, calculating the time T1 required for the charge to be charged into the hydrogen-rich carbon-cycle oxygen blast furnace until the generated molten iron is discharged from the taphole according to the effective volume of the hydrogen-rich carbon-cycle oxygen blast furnace, the daily molten iron production, the charge volume per unit molten iron, and the charge compression rate;

[0014] S3, calculating the time T2 required for the charge to move from the charge line to the tuyere center line according to the working volume of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron data, and the charge compression rate;

[0015] S4, calculating the time T3 required for the charge to move from the lower part of the furnace body to the center line of the tuyere according to the volume from the lower part of the furnace body to the center line of the tuyere of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron, and the charge compression rate data;

[0016] S5. According to the time T1, the time T2 and the time T3, calculate the thermal hysteresis time T=T3+T1-T2 of the tuyere injection of the hydrogen-rich carbon circulating oxygen blast furnace, in units of h;

[0017] S6. The thermal lag time T of the decarbonized coal gas injected from the tuyere is used as a reference in the heat balance process of the hydrogen-rich carbon circulating oxygen blast furnace.

[0018] Preferably, in step S2, the time T1=(24*Vu) / (P*v1*(1-c)), unit: h;

[0019] Where Vu represents the effective volume of the hydrogen-rich carbon cycle oxygen blast furnace, unit: m 3 ;

[0020] P represents the daily iron production of the hydrogen-rich carbon cycle oxygen blast furnace, in t / d;

[0021] v1 represents the volume of the charge for smelting 1 t of pig iron, in m 3 / t;

[0022] c represents the compression ratio, which is 12%.

[0023] Preferably, in step S3, the time T2=n1*1440*Pig / P, in h;

[0024] In the formula, n1 represents the number of batches of furnace materials that can be accommodated in the volume from the material line to the center line of the tuyere;

[0025] Pig represents the iron content of each batch of materials, in t / ch;

[0026] P represents the daily iron output of the blast furnace, unit: t / d.

[0027] Preferably, the number of batches of furnace charge n1=V1 / (v2*(1-c));

[0028] Where V1 represents the working volume of the hydrogen-rich carbon cycle oxygen blast furnace, unit: m 3 ;

[0029] v2 represents the volume of each batch of charge, in m 3 / t;

[0030] c represents the compression ratio, which is 12%.

[0031] Preferably, in step S4, the time T3=n2*1440*Pig / P, in h;

[0032] In the formula, n2 represents the number of batches of charge that can be accommodated in the volume from the lower part of the furnace body to the center line of the tuyere;

[0033] Pig represents the iron content of each batch of materials, in t / ch;

[0034] P represents the daily iron output of the blast furnace, unit: t / d.

[0035] Preferably, the number of batches of furnace charge n2=V2 / (v2*(1-c));

[0036] Where V2 represents the volume from the bottom of the furnace to the center line of the tuyere, in m 3 ;

[0037] v2 represents the volume of each batch of charge, in m 3 / t;

[0038] c represents the compression ratio, which is 12%.

[0039] Preferably, in step S6, the reference basis in the furnace heat balance process of the hydrogen-rich carbon cycle oxygen blast furnace specifically includes:

[0040] According to the thermal lag time T of the decarbonized coal gas injected at the tuyere, furnace heat adjustment actions are taken in advance, including adjusting the injected coal gas volume, coke load, humidification and other furnace heat adjustment operations, so as to maintain the furnace heat stability of the hydrogen-rich carbon circulating oxygen blast furnace.

[0041] The present invention provides a method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon-cycle oxygen blast furnace. The thermal lag time of decarbonized coal gas injected into the tuyere calculated through the actual production parameters of the hydrogen-rich carbon-cycle oxygen blast furnace is more accurate than the empirical estimated value, which provides an important reference basis for the furnace heat adjustment of the hydrogen-rich carbon-cycle oxygen blast furnace, and more accurately judges the thermal reaction time of the decarbonized coal gas injected into the hydrogen-rich carbon-cycle oxygen blast furnace, so as to take heat adjustment actions such as adjusting the coal gas volume, coke load, coal volume, and moisture content in advance to maintain the furnace heat stability of the hydrogen-rich carbon-cycle oxygen blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic flow chart of a method for calculating the thermal lag time of coal gas injected from a tuyere according to the present invention;

[0043] Figure 2 It is a schematic diagram of parameter identification of the method for calculating the thermal lag time of coal gas injected through tuyere of the present invention. DETAILED DESCRIPTION

[0044] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] The present invention provides a method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace:

[0046] According to the actual production data of the hydrogen-rich carbon circulating oxygen blast furnace, such as the billet volume, the time required for each batch of materials, the volume between the lower part of the furnace body and the center line of the tuyere, and the smelting cycle, the thermal lag time of the high-temperature quality-improving coal gas injected into the tuyere is calculated;

[0047] According to the thermal lag time and smelting cycle of decarbonized coal gas injected into the tuyere, the adjustment time of decarbonized coal gas injected into the tuyere is determined, ultimately providing an operational basis for the furnace heat adjustment of the hydrogen-rich carbon circulating oxygen blast furnace.

[0048] Combination Figure 1 and Figure 2 As shown, the method for calculating the thermal lag time of coal gas injected from a tuyere of the present invention specifically comprises the following steps:

[0049] S1. Calculate the volume of each batch of materials and the volume of materials per unit of molten iron output according to the batch weight and bulk density of sintered ore, pelletized ore, lump ore and coke in the charge of the hydrogen-rich carbon circulating oxygen blast furnace, as well as the batch iron of each batch of materials;

[0050] S2. Calculate the time T1 required for the charge to be charged into the hydrogen-rich carbon-circulating oxygen blast furnace and for the generated molten iron to be discharged from the taphole according to the effective volume of the hydrogen-rich carbon-circulating oxygen blast furnace, the daily molten iron production, the charge volume per unit molten iron, and the charge compression rate;

[0051] S3, according to the working volume of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron data, and the charge compression rate, calculate the time T2 required for the charge to move from the charge line to the center line of the tuyere;

[0052] S4, according to the volume from the bottom of the furnace body to the center line of the tuyere of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron, and the charge compression rate data, calculate the time T3 required for the charge to move from the bottom of the furnace body to the center line of the tuyere;

[0053] S5. According to time T1, time T2 and time T3, calculate the thermal hysteresis time T=T3+T1-T2 of the tuyere injection decarbonized coal gas of the hydrogen-rich carbon circulating oxygen blast furnace, in units of h;

[0054] S6. The thermal lag time T of decarbonized coal gas injected into the tuyere is used as a reference in the heat balance process of the hydrogen-rich carbon circulating oxygen blast furnace.

[0055] In the above step S2, time T1 = (24*Vu) / (P*v1*(1-c)), unit: h;

[0056] Where Vu represents the effective volume of the hydrogen-rich carbon cycle oxygen blast furnace, unit: m 3 ;

[0057] P represents the daily iron production of the hydrogen-rich carbon cycle oxygen blast furnace, in t / d;

[0058] v1 represents the volume of the charge for smelting 1 t of pig iron, in m 3 / t;

[0059] c represents the compression ratio, which is generally 12%.

[0060] In the above step S3, time T2 = n1*1440*Pig / P, unit: h;

[0061] In the formula, n1 represents the number of batches of furnace materials that can be accommodated in the volume from the material line to the center line of the tuyere;

[0062] Pig represents the iron content of each batch of materials, in t / ch;

[0063] P represents the daily iron output of the blast furnace, unit: t / d.

[0064] Number of batches of charge n1 = V1 / (v2*(1-c));

[0065] Where V1 represents the working volume of the hydrogen-rich carbon cycle oxygen blast furnace (volume from the material line to the center line of the tuyere), unit: m 3 ;

[0066] v2 represents the volume of each batch of charge, in m 3 / t;

[0067] c represents the compression ratio, which is generally 12%.

[0068] In the above step S4, time T3 = n2*1440*Pig / P, unit: h;

[0069] In the formula, n2 represents the number of batches of charge that can be accommodated in the volume from the lower part of the furnace body to the center line of the tuyere;

[0070] Pig represents the iron content of each batch of materials, in t / ch;

[0071] P represents the daily iron output of the blast furnace, unit: t / d.

[0072] Number of batches of charge n2 = V2 / (v2*(1-c));

[0073] Where V2 represents the volume from the bottom of the furnace to the center line of the tuyere, in m 3 ;

[0074] v2 represents the volume of each batch of charge, in m 3 / t;

[0075] c represents the compression ratio, which is generally 12%.

[0076] In the above step S6, the reference basis for the furnace heat balance process of the hydrogen-rich carbon cycle oxygen blast furnace specifically includes:

[0077] The blast furnace operator can combine the basic furnace heat conditions of the hydrogen-rich carbon circulating oxygen blast furnace and take furnace heat adjustment actions in advance according to the thermal lag time T of the decarbonized coal gas injected at the tuyere, including adjusting the injected gas volume, coke load, humidification and other furnace heat adjustment operations, so as to maintain the furnace heat stability of the hydrogen-rich carbon circulating oxygen blast furnace.

[0078] Example

[0079] 1) Take a certain 400m 3 Take the hydrogen-rich carbon cycle oxygen blast furnace as an example, with a daily output of 1800t / d, ore batch 18t / ch, coke batch 4t / ch, O / C: 4.5, and a batch charge volume of 16.98m 3 / ch, the compression rate of the charge is calculated as 12%, and the volume of each batch of charge after compression is 14.94m 3 / ch, the time T1 required from charging charge into blast furnace to producing molten iron and discharging from taphole is 4.4h.

[0080] 2) The time required for the charge to travel from the material line to the center line of the tuyere is T2, and the volume from the material line to the center line of the tuyere is 305m 3 The average number of batches of material unloaded per hour is 6.6ch / h, and the time T2 required for the charge to move from the material line to the center line of the tuyere is 3.1h.

[0081] 3) Volume from the bottom of the furnace to the center line of the tuyere: 174m 3 According to the compressed volume of each batch of materials and the number of batches unloaded per hour, the time it takes for the charge to travel from the bottom of the furnace body to the center line of the tuyere is calculated to be 1.7 hours.

[0082] 4) Based on the above calculations of the time from charging the charge into the blast furnace to the time when the molten iron is discharged from the iron mouth, the time from the charge line to the center line of the tuyere, and the time from the lower part of the furnace body to the center line of the tuyere, the thermal lag time of gas injection at the tuyere of the blast furnace is calculated to be 3h. As shown in the following table:

[0083]

[0084] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace, characterized in that: According to the billet volume of the hydrogen-rich carbon circulating oxygen blast furnace, the time required for each batch of materials, the volume between the lower part of the furnace body and the center line of the tuyere, and the smelting cycle, the thermal lag time of the high-temperature quality-improving coal gas injected from the tuyere is calculated; According to the thermal lag time and smelting cycle of the decarbonized coal gas injected into the tuyere, the adjustment time of the decarbonized coal gas injected into the tuyere is determined, and finally an operating basis is provided for the furnace heat adjustment of the hydrogen-rich carbon circulating oxygen blast furnace.

2. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The method for calculating the thermal lag time of gas injection from the tuyere specifically comprises the following steps: S1, according to the batch weight and bulk density of sintered ore, pelletized ore, lump ore and coke in the charge of the hydrogen-rich carbon circulating oxygen blast furnace, as well as the batch iron of each batch, calculate the volume of each batch of materials and the charge volume per unit molten iron output; S2, calculating the time T1 required for the charge to be charged into the hydrogen-rich carbon-cycle oxygen blast furnace until the generated molten iron is discharged from the taphole according to the effective volume of the hydrogen-rich carbon-cycle oxygen blast furnace, the daily molten iron production, the charge volume per unit molten iron, and the charge compression rate; S3, calculating the time T2 required for the charge to move from the charge line to the tuyere center line according to the working volume of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron data, and the charge compression rate; S4, calculating the time T3 required for the charge to move from the lower part of the furnace body to the center line of the tuyere according to the volume from the lower part of the furnace body to the center line of the tuyere of the hydrogen-rich carbon cycle oxygen blast furnace, the volume of each batch of charge, the daily iron production and batch iron, and the charge compression rate data; S5. According to the time T1, the time T2 and the time T3, calculate the thermal hysteresis time T=T3+T1-T2 of the tuyere injection of the hydrogen-rich carbon circulating oxygen blast furnace, in units of h; S6. The thermal lag time T of the decarbonized coal gas injected from the tuyere is used as a reference in the heat balance process of the hydrogen-rich carbon circulating oxygen blast furnace.

3. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 2, characterized in that: In the step S2, the time T1=(24*Vu) / (P*v1*(1-c)), unit: h; Where Vu represents the effective volume of the hydrogen-rich carbon cycle oxygen blast furnace, unit: m 3 ; P represents the daily iron production of the hydrogen-rich carbon cycle oxygen blast furnace, in t / d; v1 represents the volume of the charge for smelting 1 t of pig iron, in m 3 / t; c represents the compression ratio, which is 12%.

4. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 3, characterized in that: In the step S3, the time T2=n1*1440*Pig / P, unit: h; In the formula, n1 represents the number of batches of furnace materials that can be accommodated in the volume from the material line to the center line of the tuyere; Pig represents the iron content of each batch of materials, in t / ch; P represents the daily iron output of the blast furnace, unit: t / d.

5. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 4, characterized in that: The number of batches of furnace charge n1=V1 / (v2*(1-c)); Where V1 represents the working volume of the hydrogen-rich carbon cycle oxygen blast furnace, unit: m 3 ; v2 represents the volume of each batch of charge, in m 3 / t; c represents the compression ratio, which is 12%.

6. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 5, characterized in that: In the step S4, the time T3=n2*1440*Pig / P, unit: h; In the formula, n2 represents the number of batches of charge that can be accommodated in the volume from the lower part of the furnace body to the center line of the tuyere; Pig represents the iron content of each batch of materials, in t / ch; P represents the daily iron output of the blast furnace, unit: t / d.

7. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 6, characterized in that: The number of batches of furnace charge n2=V2 / (v2*(1-c)); Where V2 represents the volume from the bottom of the furnace to the center line of the tuyere, in m 3 ; v2 represents the volume of each batch of charge, in m 3 / t; c represents the compression ratio, which is 12%.

8. The method for calculating the thermal lag time of coal gas injected into the tuyere of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 2, characterized in that: In the step S6, the reference basis for the furnace heat balance process of the hydrogen-rich carbon circulating oxygen blast furnace specifically includes: According to the thermal lag time T of the decarbonized coal gas injected at the tuyere, furnace heat adjustment actions are taken in advance, including adjusting the injected coal gas volume, coke load, humidification and other furnace heat adjustment operations, so as to maintain the furnace heat stability of the hydrogen-rich carbon circulating oxygen blast furnace.

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