Calculation method for determining insertion depth of tuyere in blast furnace

Abstract

The invention mainly relates to the technical field of blast furnace smelting. In order to quickly and accurately determine the blast furnace tuyere insertion depth, the invention provides a calculation method for determining the blast furnace tuyere insertion depth, the tuyere insertion depth is obtained when uniform initial center airflow and edge airflow are formed on a tuyere plane by blast furnace rotation area airflow, and the tuyere insertion depth is taken as the minimum tuyere insertion depth; obtaining the tuyere insertion depth when the convolution areas of different tuyeres on the tuyere plane of the blast furnace are just not overlapped, and taking the tuyere insertion depth as the maximum tuyere insertion depth; the actual tuyere insertion depth of the blast furnace is determined according to the minimum tuyere insertion depth and the maximum tuyere insertion depth so as to assist a blast furnace designer in determining the tuyere insertion depth, meanwhile, a blast furnace operator can evaluate and optimize the tuyere insertion depth of the blast furnace put into production, and then the operation stability and smelting efficiency of the blast furnace are improved.

Description

Technical Field

[0001] The invention mainly relates to the technical field of blast furnace smelting, and in particular to a calculation method for determining the insertion depth of a tuyere in a blast furnace. Background Art

[0002] Blast furnace ironmaking is a comprehensive process. Each process parameter design has different degrees of influence on blast furnace production. Blast furnace tuyere is one of the important air supply equipment for ironmaking blast furnaces. Tuyere has existed since the blast furnace ironmaking production process. Blast furnace blast and injected fuel all enter the blast furnace through the tuyere. Tuyere parameters mainly include data such as the number, height, diameter, angle and length of tuyere. Tuyere parameters have an important influence on its own life and the technical and economic indicators of ironmaking blast furnace production, and are one of the important means of adjusting the lower part of the blast furnace. The length of blast furnace tuyere is one of the important parameters of tuyere design, which includes two concepts. One is the length of the finished product of the tuyere sleeve, and the other is the length of the tuyere sleeve deep into the furnace, that is, the insertion depth of the tuyere.

[0003] The selection of tuyere insertion depth not only affects the distribution of coal gas flow and the descending speed of charge, but also directly affects the service life and installation convenience of the tuyere. However, there are currently few methods for calculating the tuyere insertion depth, and there is no strict theoretical calculation formula. Blast furnace designers at home and abroad generally determine the tuyere insertion depth by analogy with similar blast furnaces that have been put into production. In actual operation, it is difficult to determine the optimal tuyere insertion depth value, which in turn affects the stable operation of the blast furnace and the smelting efficiency. Summary of the invention

[0004] Technical Problems to be Solved by the Invention

[0005] The invention provides a calculation method for determining the insertion depth of a tuyere in a blast furnace, aiming at quickly and accurately determining the insertion depth of the tuyere in the blast furnace.

[0006] The technical solution adopted by the present invention to solve the above technical problems

[0007] A calculation method for determining the insertion depth of a tuyere in a blast furnace comprises:

[0008] Obtain the corresponding tuyere insertion depth when the blast furnace cyclone airflow forms a uniform initial central airflow and edge airflow on the tuyere plane, and use it as the minimum tuyere insertion depth L min ;

[0009] Obtain the corresponding tuyere insertion depth when the raceways of different tuyere on the blast furnace tuyere plane are in contact and do not overlap, and use it as the maximum tuyere insertion depth L max ;

[0010] Determine the actual tuyere insertion depth L of the blast furnace according to the minimum tuyere insertion depth and the maximum tuyere insertion depth opt .

[0011] Furthermore, the minimum tuyere insertion depth is specifically: where d B is the furnace diameter, θ is the blast furnace tuyere angle, D R is the depth of the raceway of blast furnace tuyere, and λ is the set insertion depth adjustment coefficient.

[0012] Furthermore, the maximum tuyere insertion depth is specifically: where d B is the furnace diameter, θ is the blast furnace tuyere angle, D R is the depth of the blast furnace tuyere raceway, W is the width of the blast furnace tuyere raceway, and n is the number of tuyere in the blast furnace.

[0013] Furthermore, the actual tuyere insertion depth of the blast furnace is:

[0014] Furthermore, the depth of the blast furnace tuyere raceway is Where K is the correction coefficient of the set tuyere raceway depth, n is the number of tuyere in the blast furnace, Q is the number of blasts, ρ g is the blast density, θ is the blast furnace tuyere angle, d F is the diameter of the tuyere, g is the acceleration due to gravity, d c is the charge particle diameter, is the coke shape factor, ε is the porosity, ρ c is the bulk density of charge.

[0015] Furthermore, the width of the blast furnace tuyere raceway is Where K0 is the correction coefficient of the set tuyere raceway width, d F is the diameter of the air outlet.

[0016] Furthermore, the value range of the insertion depth adjustment coefficient λ is 0.1 to 0.2.

[0017] Beneficial effects of the present invention

[0018] The calculation method for determining the insertion depth of tuyere in a blast furnace described in the present invention can calculate the ideal selection range of tuyere insertion depth of the blast furnace through simple calculation by utilizing partial structure and process parameters of the blast furnace, and select the optimal tuyere insertion depth of the blast furnace within the ideal selection range of tuyere insertion depth, which can assist blast furnace designers in quickly determining the optimal insertion depth of the tuyere, and is also beneficial for blast furnace operators to evaluate and optimize the tuyere insertion depth of the put into production blast furnace, thereby improving the stability of blast furnace operation and smelting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a calculation method for determining the insertion depth of a tuyere in a blast furnace. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, a calculation method for determining the insertion depth of a tuyere in a blast furnace described in the present invention specifically includes the following steps.

[0021] Step S1: Collect the structural parameters and process parameter data of the blast furnace, including: blast volume Q, m 3 / s; number of tuyere n, pcs; furnace diameter d B , m; tuyere diameter d F , m; tuyere angle θ, radians; charge packing density ρ c ,kg / m 3 ; Blast density ρ g ,kg / m 3 ; Gravitational acceleration g, m / s 2 ; Charge particle diameter d c , m; is the coke shape coefficient, which is generally 1.72; ε is the porosity; K is the set tuyere raceway depth correction coefficient, which is a constant and can be selected according to the actual situation of the blast furnace, and is initially 0.70. The values ​​of the above parameters in this embodiment are specifically shown in Table 1:

[0022] Table 1 Structure and process parameters of blast furnace

[0023]

[0024]

[0025] Step S2: Calculate the depth D of the tuyere raceway of the blast furnace according to the structural parameters and process parameter data of the blast furnace collected in step 1 R The specific calculation method is In this embodiment, the depth D of the tuyere raceway of the blast furnace is calculated based on the above parameter values. R =1.035m.

[0026] Step S3: Based on the data in Table 1 and the depth D of the tuyere raceway of the blast furnace calculated in step 2 R Calculation of the Width of the Tuyere Raceway of a Blast Furnace Wherein K0 is the set tuyere raceway width correction coefficient. In this embodiment, the value of K0 is 2.31, and the calculated blast furnace tuyere raceway depth W=0.863m.

[0027] Step S4: Calculate the minimum tuyere insertion depth. After the tuyere sleeve is inserted into the furnace, the uniformity of the initial gas flow distribution in the blast furnace must be met. The depth of the tuyere raceway is required to enable the air flow in the raceway to form a uniform initial central airflow and edge airflow on the tuyere plane, that is, (D R +L)cosθ≥λdB , then the tuyere insertion depth Therefore, the minimum tuyere insertion depth is Where λ is the set insertion depth adjustment coefficient. As a preferred embodiment, λ is between 0.1 and 0.2. The value of the insertion depth adjustment coefficient λ in this embodiment is Based on the parameters calculated in step S1 to step S3, the minimum tuyere insertion depth L in this embodiment is calculated. min =0.210m.

[0028] Step S5: Calculate the maximum tuyere insertion depth. In actual operation, the tuyere sleeve should not only meet the uniformity of the initial gas flow distribution of the blast furnace after being inserted into the furnace, but also meet the rationality of the distribution of the tuyere combustion zone, and require that the whirlpool zones of different tuyere on the tuyere plane do not overlap, that is, (d B -2cosθ-2Lcosθ)π≥nW, then the tuyere insertion depth needs to meet Therefore, the maximum tuyere insertion depth is The maximum tuyere insertion depth L calculated in this embodiment max =0.733m.

[0029] Step S6: The range of the tuyere insertion depth of the blast furnace can be known according to the minimum tuyere insertion depth calculated in step S4 and the maximum tuyere insertion depth calculated in step S5. Preferably, the optimal tuyere insertion depth of the blast furnace is set to In this embodiment, according to the minimum insertion depth and the maximum insertion depth calculated in step S4 and step S5, it can be known that the insertion depth of the blast furnace tuyere should be in the range of 0.210-0.733m, wherein the optimal insertion depth Lopt is 0.472m. By comparison, the current insertion depth of the tuyere of the blast furnace is 450mm, which is within the range of the calculation results and close to the optimal value, indicating that the selection of the insertion depth of the blast furnace tuyere is more appropriate.

[0030] Step S7: The structure and process parameter data of the blast furnace obtained in steps S1 to S6, and the raceway depth D calculated are R and width W, and minimum tuyere insertion depth L min , Maximum air inlet insertion depth L max and based on the minimum tuyere insertion depth L min and maximum tuyere insertion depth L max The obtained optimal tuyere insertion depth Lopt is stored in the database for easy subsequent parameter retrieval.

Claims

1. A calculation method for determining the insertion depth of tuyere in a blast furnace, characterized in that: include: Obtain the corresponding tuyere insertion depth when the blast furnace cyclone airflow forms a uniform initial central airflow and edge airflow on the tuyere plane, and use it as the minimum tuyere insertion depth L min ; Obtain the corresponding tuyere insertion depth when the raceways of different tuyere on the blast furnace tuyere plane are in contact and do not overlap, and use it as the maximum tuyere insertion depth L max ; Determine the actual tuyere insertion depth L according to the minimum tuyere insertion depth and the maximum tuyere insertion depth opt .

2. A calculation method for determining the insertion depth of tuyere in a blast furnace according to claim 1, characterized in that: The minimum tuyere insertion depth is specifically: where d B is the furnace diameter, θ is the blast furnace tuyere angle, D R is the depth of the raceway of blast furnace tuyere, and λ is the set insertion depth adjustment coefficient.

3. A calculation method for determining the insertion depth of tuyere in a blast furnace according to claim 1, characterized in that: The maximum tuyere insertion depth is specifically: where d B is the furnace diameter, θ is the blast furnace tuyere angle, D R is the depth of the blast furnace tuyere raceway, W is the width of the blast furnace tuyere raceway, and n is the number of tuyere in the blast furnace.

4. A calculation method for determining the insertion depth of a tuyere in a blast furnace according to any one of claims 1 to 3, characterized in that: The actual tuyere insertion depth is:

5. A calculation method for determining the insertion depth of a tuyere in a blast furnace according to claim 2 or 3, characterized in that: Depth of the blast furnace tuyere raceway Where K is the correction coefficient of the set tuyere raceway depth, n is the number of tuyere in the blast furnace, Q is the number of blasts, ρ g is the blast density, θ is the blast furnace tuyere angle, d F is the diameter of the tuyere, g is the acceleration due to gravity, d c is the charge particle diameter, is the coke shape factor, ε is the porosity, ρ c is the bulk density of charge.

6. A calculation method for determining the insertion depth of tuyere in a blast furnace according to claim 3, characterized in that: The width of the blast furnace tuyere raceway Where K0 is the correction coefficient of the set tuyere raceway width, d F is the diameter of the air outlet.

7. A calculation method for determining the insertion depth of tuyere in a blast furnace according to claim 2, characterized in that: The value range of the insertion depth adjustment coefficient λ is 0.1-0.2.

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