METHOD FOR DETECTING AIR FLOW DISTRIBUTION IN BLAST FURNACE

Abstract

A method for detecting an air flow distribution in a blast furnace, taking into account a heat exchange between an air flow and a solid material bed and the effect of a distribution of a material layer structure in a radial direction of a blast furnace on the radial air permeability of blast furnace, which affects a mode of air flow distribution, wherein the distribution of the air flow and the radial material layer structure of the blast furnace can be calculated by combining a cross-shaped temperature-measuring gun and other main blast furnace operating parameters. According to the detection method, a blast furnace operator can timely and accurately infer, from a change in a current radial air flow temperature distribution, the direction of change of the distribution of the air flow and the radial material layer structure at a furnace throat portion.

Claims

1. A method for detecting gas flow distribution in blast furnace, wherein the method comprises the following steps: a) dividing a cross-section of blast furnace throat according to the number and positions of temperature-measuring devices at the top of blast furnace to obtain N temperature-measuring device regions; wherein the N is a natural number greater than or equal to 1; b) obtaining a solid-gas heat flow ratio of each of the temperature-measuring device regions according to temperature values from each of the temperature-measuring devices and a balance equation between a heat flow rate of gas and a heat flow rate of solid in a lump zone of blast furnace below corresponding temperature-measuring device region; c) establishing a function relation between a thickness ratio of burden material layers and a gas flow rate within each of the temperature-measuring device regions according to the solid-gas heat flow ratio of each of the temperature-measuring device regions; d) obtaining the thickness ratio of burden material layers within each of the temperature-measuring device regions according to pressure drop per unit length of burden layer, particle size distribution of the burden materials and gas resistance equation of each lump zone of blast furnace, and obtaining the gas flow rate of each of the temperature-measuring device regions according to the thickness ratio of burden material layers within each of the temperature-measuring device region above and the function relation between the thickness ratio of burden material layers and the gas flow rate within each of the temperature-measuring device region obtained in the above step c); and e) plotting the region distribution of each of the temperature-measuring device regions and the gas flow rate thereof, to obtain a detection result of the gas distribution.

2. The method according to claim 1, wherein the method further comprises, after step d): d#) obtaining by calculation an average thickness ratio of burden material layers according to the thickness ratio of burden material layers within each of the temperature-measuring device regions, and obtaining a total volume of gas flow passing through the temperature-measuring device regions according to gas flow rate in each of the temperature-measuring device regions, to further obtain a total heat of gas flow passing through the temperature-measuring device regions; comparing the average thickness ratio of burden material layers obtained in the above step with a theoretical average thickness ratio of burden material layers, to obtain an error σ1; comparing the total volume of gas flow passing through the temperature-measuring device regions obtained in the above step with a theoretical total volume of furnace top gas flow, to obtain an error σ2; and comparing the total heat of gas flow passing through the temperature-measuring device regions with a theoretical total heat of furnace top gas flow, to obtain an error σ3; modifying the pressure drop per unit length of burden layer and the particle size distribution of burden materials if one or more of the errors σ1, σ2, and σ3 has a value greater than or equal to 5%, and performing the step d) again, until the value of each of the errors σ1, σ2, and σ3 is less than 5%; and performing the above step e) if the value of each of the errors σ1, σ2, and σ3 is less than 5%.

3. The method according to claim 2, wherein the burden materials are ore and coke, and the theoretical average thickness ratio of burden material layers is calculated based on the formula: X.sub.0=[L.sub.O/(L.sub.O+L.sub.C)].sub.0, wherein Lo is a thickness of ore layer, and Lc is a thickness of coke layer.

4. The method according to claim 2, wherein the thickness ratio of burden material layers within each of the temperature-measuring device regions is x.sub.i, the average thickness ratio of burden material layers is X.sub.t, and the average thickness ratio of burden material layers is calculated based on the formula: $X_t=\underset{i=1}{\overset{N}{.Math.}}.Math.x_i.Math.S_i.Math.\text{/}.Math.A$ wherein S.sub.i is an area of each of the temperature-measuring device regions, and A is a total area of the cross-section of the blast furnace throat.

5. The method according to claim 1, wherein the burden materials are ore and coke, the thickness ratio of burden material layers in the temperature-measuring device region is x.sub.i, the gas flow rate in the temperature-measuring device region is u.sub.i, then the function relation between the thickness ratio of burden material layers and the gas flow rate in the temperature-measuring device region is: $x_i={\left(\frac{C_s.Math.G_s}{C_g.Math.G_g}\right)}_i.Math.\frac{{\left(C_g\right)}_i.Math.{\left({\rho }_g\right)}_i}{C_s\left({\rho }_O-{\rho }_C\right).Math.v_i}.Math.u_i-\frac{{\rho }_C}{\left({\rho }_O-{\rho }_C\right)}$ wherein C.sub.g is a specific heat of gas, C.sub.s is a specific heat of solid, G.sub.g is a flow rate of gas, G.sub.s is a flow rate of solid, ρ is a density of furnace top gas, v is a descent velocity of a solid burden bed, ρ.sub.O is a density of ore, and ρ.sub.C is a density of coke.

6. The method according to claim 1, wherein the gas resistance equation of each lump zone of blast furnace is: ${\left(\frac{\Delta .Math..Math.P}{L}\right)}_i={\left[k_1^{\star }.Math.\frac{{\left(1-\mathrm{.Math.}\right)}^2}{D_p^2.Math.{\mathrm{.Math.}}^3}.Math.\mu .Math..Math.u+k_2^{\star }.Math.\frac{\left(1-\mathrm{.Math.}\right)}{D_p.Math.{\mathrm{.Math.}}^3}.Math.\rho .Math..Math.u^2\right]}_i$ wherein, k.sub.1* is a viscous resistance coefficient, k.sub.2* is an inertia resistance coefficient, ΔP/L is a pressure drop per unit length, ε is a burden bed porosity, D.sub.p is an average particle diameter of particles, μ is a gas viscosity, u is a gas flow rate, and ρ is a gas density; the viscous resistance coefficient and the inertia resistance coefficient of the coke are respectively:
k.sub.1*=450.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=2.2.Math.(D.sub.p.Math.10).sup.0.04; the viscous resistance coefficient and the inertia resistance coefficient of the ore are respectively:
k.sub.1*=260.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=1.2.Math.(D.sub.p.Math.10).sup.0.04.

7. The method according to claim 1, wherein the pressure drop per unit length of burden layer in each lump zone of blast furnace is equal, the pressure drop per unit length of burden layer in each lump zone of blast furnace is equal to the sum of a pressure drop per unit length of coke layer and a pressure drop per unit length of ore layer in said lump zone of blast furnace.

8. The method according to claim 1, wherein the temperature-measuring device is a cross-shaped temperature-measuring gun.

9. A system for detecting gas flow distribution in blast furnace, wherein the system comprises: a division unit, configured to divide a cross-section of blast furnace throat according to the number and positions of temperature-measuring devices at the top of blast furnace to obtain N temperature-measuring device regions; wherein the N is a natural number greater than or equal to 1; a first attainment unit, configured to obtain a solid-gas heat flow ratio of each of the temperature-measuring device regions according to temperature values from each of the temperature-measuring devices and a balance equation between a heat flow rate of gas and a heat flow rate of solid in a lump zone of blast furnace below corresponding temperature-measuring device region; an establishment unit, configured to establish a function relation between a thickness ratio of burden material layers and a gas flow rate within each of the temperature-measuring device regions according to the solid-gas heat flow ratio of each of the temperature-measuring device regions; a second attainment unit, configured to obtain the thickness ratio of burden material layers within each of the temperature-measuring device regions according to pressure drop per unit length of burden layer, particle size distribution of the burden materials and gas resistance equation of each lump zone of blast furnace, and to obtain the gas flow rate of each of the temperature-measuring device regions according to the thickness ratio of burden material layers within each of the temperature-measuring device region above and the function relation between the thickness ratio of burden material layers and the gas flow rate within each of the temperature-measuring device region obtained in the above step c); and a result unit, configured to plot the above distribution of each of the temperature-measuring device regions and the gas flow rate thereof, to obtain a detection result of the gas distribution.

10. The detection system according to claim 9, wherein the system further comprises: a verification unit, configured to obtain by calculation an average thickness ratio of burden material layers according to the thickness ratio of burden material layers within each of the temperature-measuring device regions, and to obtain a total volume of gas flow passing through the temperature-measuring device regions according to gas flow rate in each of the temperature-measuring device regions, to further obtain a total heat of gas flow passing through the temperature-measuring device regions; wherein the average thickness ratio of burden material layers obtained in the above step is compared with a theoretical average thickness ratio of burden material layers, to obtain an error σ1; the total volume of gas flow passing through the temperature-measuring device regions obtained in the above step is compared with a theoretical total volume of furnace top gas flow, to obtain an error σ2; and the total heat of gas flow passing through the temperature-measuring device regions is compared with a theoretical total heat of furnace top gas flow, to obtain an error σ3; the pressure drop per unit length of burden layer and the particle size distribution of burden materials are modified if one or more of the errors σ1, σ2, and σ3 has a value greater than or equal to 5%, and the step d) is performed again, until the value of each of the errors σ1, σ2, and σ3 is less than 5%; and the step e) is performed in the case that the value of each of the errors σ1, σ2, and σ3 is less than 5%.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0044] FIG. 1 is a diagram showing the arrangement of cross-shaped temperature-measuring guns and the layout of radial temperature measuring regions;

[0045] FIG. 2 is a schematic view showing the division of internal regions of a blast furnace and gas-solid heat balance in the blast furnace blank zone according to the present application;

[0046] FIG. 3 shows the position of the burden materials and the moving directions of the solid and gas, and the positions where the on-line monitoring is performed within the blast furnace according to the present application;

[0047] FIG. 4 shows area of each of regions divided by the temperature-measuring device regions according to Example 1 of the present application;

[0048] FIG. 5 is a diagram showing the distribution of a radial descent velocity of blast furnace burden according to Example 1 of the present application;

[0049] FIG. 6 shows an operation situation of a blast furnace of Hongfa 2500# according to the present application from the end of 2013 to early 2014;

[0050] FIG. 7 shows change of respective parameters from case 1 to case 2 according to the present application;

[0051] FIG. 8 shows change of respective parameters from case 2 to case 3 according to the present application;

[0052] FIG. 9 shows change of respective parameters from case 3 to case 4 according to the present application; and

[0053] FIG. 10 shows change of respective parameters from case 4 to case 5 according to the present application.

DETAILED DESCRIPTION OF THE INVENTION

[0054] For further understanding the present application, the preferred embodiments of the present application are described hereinafter with reference to examples of the present application; however, these descriptions are presented only for further explaining features and advantages of the present application, rather than limiting the claims of the present application.

[0055] The present application discloses a method for detecting gas flow distribution in blast furnace, characterized in comprising the following steps:

[0056] a) dividing a cross-section of blast furnace throat according to the number and positions of temperature-measuring devices at the top of blast furnace to obtain N temperature-measuring device regions; wherein the N is a natural number greater than or equal to 1;

[0057] b) obtaining a solid-gas heat flow ratio of each of the temperature-measuring device regions according to temperature values from each of the temperature-measuring devices and a balance equation between a heat flow rate of gas and a heat flow rate of solid in a lump zone of blast furnace below corresponding temperature-measuring device region;

[0058] c) establishing a function relation between a thickness ratio of burden material layers and a gas flow rate within each of the temperature-measuring device regions according to the solid-gas heat flow ratio of each of the temperature-measuring device regions;

[0059] d) obtaining the thickness ratio of burden material layers within each of the temperature-measuring device regions according to pressure drop per unit length of burden layer, particle size distribution of the burden materials and gas resistance equation of each lump zone of blast furnace, and obtaining the gas flow rate of each of the temperature-measuring device regions according to the thickness ratio of burden material layers within each of the temperature-measuring device region above and the function relation between the thickness ratio of burden material layers and the gas flow rate within each of the temperature-measuring device region obtained in the above step c); and

[0060] e) plotting the region distribution of each of the temperature-measuring device regions and the gas flow rate thereof, to obtain a detection result of the gas distribution.

[0061] There are no particular requirements on definitions of the symbols and concepts used in the present application, as long as they are common symbols and concepts well known to those skilled in the art.

[0062] There are no particular requirements on the thermodynamic calculation formulas mentioned in the present application, as long as they are thermodynamic calculation formulas well known to those skilled in the art.

[0063] In the present application, first, the cross-section of blast furnace throat is divided according to the number and positions of temperature-measuring devices at the top of blast furnace to obtain N temperature-measuring device regions; wherein the N is a natural number greater than or equal to 1.

[0064] There are no particular limitations on the blast furnace with the temperature-measuring device, as long as it is an iron-making blast furnace well known to those skilled in the art, but is preferably a blast furnace with 2500 m.sup.3 from Hongfa in the present application. There are no particular limitations on the temperature-measuring device in the present application, as long as it is a device for measuring the temperature of blast furnaces well known to those skilled in the art, and is preferably a cross-shaped temperature-measuring gun according to the present application. In the present application, there are no particular limitations on the number of the cross-shaped temperature-measuring gun, as long as it is a common number of cross-shaped temperature-measuring gun well known to those skilled in the art, and is preferably 2 to 4 according to the present application. In the present application, there are no particular limitations on the number of temperature-measuring points of the cross-shaped temperature-measuring gun, as long as it is a common number of temperature-measuring points of a cross-shaped temperature-measuring gun well known to those skilled in the art, and is preferably 5 to 8, and more preferably 6 to 7 according to the present application. In the present application, there are no particular limitations on the position of the cross-shaped temperature-measuring gun, as long as it is a position of a cross-shaped temperature-measuring gun mounted in blast furnace well known to those skilled in the art, but the cross-shaped temperature-measuring guns are preferably mounted correspondingly to the four walls of blast furnace throat, and more preferably to the east side and the west side, and more preferably the south side and the north side, and most preferably the east, south, west and north sides according to the present application. In the present application, there are no particular limitations on the overall mounting position of the temperature-measuring device, as long as it is the overall mounting position well known to those skilled in the art, and in particular, is preferred in the present application that one cross-shaped temperature-measuring gun is mounted in each of the four directions, i.e., east, south, west and north, of blast furnace throat, in which one cross-shaped temperature-measuring gun has six temperature-measuring points, and each of the other three cross-shaped temperature-measuring guns has five temperature-measuring points. In the present application, there are no particular limitations on the method for setting the temperature-measuring points, as long as it is a method for setting temperature-measuring points of cross-shaped temperature-measuring guns well known to those skilled in the art. The specific method for setting the temperature-measuring points in the present application is preferably implemented in the following steps: the temperature-measuring gun is mounted to be inclined downwards by 15 degrees, and the temperature-measuring points are arranged equidistantly from the center to the edge in a radial direction of blast furnace throat, the space between every two cross-shaped temperature-measuring guns is preferably ranging from 500 mm to 1000 mm, more preferably 600 mm to 900 mm, and most preferably 800 mm. In the present application, there are no particular limitations on the radial direction, as long as it is a radial direction well known to those skilled in the art. The radial direction described in the present application is a radial direction from the center of blast furnace throat to the furnace wall, and the radial direction may be in parallel with a horizontal plane, and may also be not in parallel with a horizontal plane.

[0065] In the present application, there are no particular limitations on the specific number of the temperature-measuring device regions, i.e., the specific value of the N, which can be set as desired by those skilled in the art according to the size of blast furnace and the practical production situation, and is preferably 4 to 8, more preferably 5 to 7, and most preferably 6 according to the present application. In the present application, there are no particular limitations on the method for dividing the regions, as long as it is a method for dividing the temperature-measuring device regions of the cross-shaped temperature-measuring guns well known to those skilled in the art. The specific division method according to the present application is preferably implemented according to the following steps, first, the center of the cross-section of blast furnace throat is taken as a center of circle, and a distance from the center of blast furnace to the middle of every two temperature-measuring points is taken as a radius to draw circles, the cross-section of the furnace throat is divided into six regions along a radial direction, and the areas of the regions are S.sub.1, S.sub.2, S.sub.3, S.sub.4, S.sub.5, S.sub.6, respectively. In each of the temperature-measuring device regions, the temperature points corresponding to the four temperature-measuring guns in the four directions are averaged, i.e., the temperature value of each of the temperature-measuring device regions, to finally obtain the temperature distribution of furnace top gas in the radial direction of the throat.

[0066] Reference may be made to FIG. 1 for the preferred embodiments of the cross-shaped temperature-measuring guns and the division of the temperature-measuring device regions in the radial direction as described above. FIG. 1 is a diagram showing the arrangement of the temperature-measuring guns and the layout of the radial temperature-measuring device regions.

[0067] In the present application, after the temperature-measuring device regions are divided by the above method, a solid-gas heat flow ratio of each of the temperature-measuring device regions is obtained according to temperature values from each of the temperature-measuring devices and a balance equation between a heat flow rate of gas and a heat flow rate of solid in a lump zone of blast furnace below corresponding temperature-measuring device region.

[0068] In the present application, a heat balance may be reached at the part of the lump zone of blast furnace, that is, the temperatures of the solid and the gas are very close to each other, i.e., no heat transfer is happened between the solid and the gas, and this region is a heat balance region. If ignoring the heat loss caused by the chemical reaction and the heat exchange with the furnace wall, a balance equation between the heat flow rate of gas and the heat flow rate of solid is established. The balance equation between the heat flow rate of gas and the heat flow rate of solid is preferably:

C.sub.gG.sub.g(dT/dZ)=C.sub.sG.sub.s(dt/dZ),

wherein Cg is a specific heat of gas, in a unit of KJ/m.sup.3.Math.° C.; C.sub.s is a specific heat of solid, in a unit of kJ/kg.Math.° C.; G.sub.g is a flow rate of gas, in a unit of Nm.sup.3/h; G.sub.s is a flow rate of solid, in a unit of kg/h; dT/dZ is a temperature change per unit of gas height, in a unit of ° C./m; and dt/dZ is a temperature change per unit of solid height, in a unit of ° C./m.

[0069] In the present application, each of the temperature-measuring points meets the above balance equation between the heat flow rate of gas and the heat flow rate of solid, i.e., the gas-solid heat balance equation. Each of the temperature values of the cross-shaped temperature-measuring guns above are imported into the balance equation, the solid-gas heat flow ratios C.sub.sG.sub.s/C.sub.gG.sub.g at various points in the radial direction of the cross-shaped temperature-measuring guns can be calculated, that is, the solid-gas heat flow ratios of corresponding temperature-measuring device regions above the lump zone of blast furnace. The equation of the solid-gas heat flow ratio is C.sub.sG.sub.s/C.sub.gG.sub.g, i=1*N. The corresponding temperature-measuring device regions mean that the temperature-measuring device regions have one-to-one correspondence to the lump zone of blast furnace in the height direction of blast furnace, and are located above the corresponding lump zone of blast furnace. Any one of the temperature-measuring device regions is the i.sup.th region, and 1≦i≦N; and the i is a natural number greater than or equal to 1.

[0070] In the present application, there are no particular limitations on the lump zone of blast furnace; as long as they are lump zones of blast furnace well known to those skilled in the art. In the present application, there are no particular limitations on the subsequent division of the internal regions of blast furnace, which may be performed by a division method well known to those skilled in the art. The blast furnace is preferably divided according to the present application into five parts, i.e., lump zone, cohesive zone, dripping zone, raceway zone, as well as slag-iron zone, reference may be particularly made to FIG. 2 for the temperature distribution of the solid and gas inside the blast furnace, and FIG. 2 is a schematic view showing the division of the internal regions of blast furnace and the gas-solid heat balance in the lump zones of blast furnace according to the present application.

[0071] In the present application, the function relation between the thickness ratio of burden material layers and the gas flow rate within each of the temperature-measuring device regions is established according to the solid-gas heat flow ratio of each of the temperature-measuring device regions obtained in the above step. The burden materials are preferably ore and coke. The thickness ratio of burden material layers in the temperature-measuring device region is preferably x.sub.i, and the gas flow rate in the temperature-measuring device region is preferably u.sub.i. The function relation between the thickness ratio of burden material layers and the gas flow rate in the temperature-measuring device region is preferably:

[00004]$x_i={\left(\frac{C_s.Math.C_s}{C_g.Math.C_g}\right)}_i.Math.\frac{{\left(C_g\right)}_i.Math.{\left({\rho }_g\right)}_i}{C_s\left({\rho }_O-{\rho }_C\right).Math.v_i}.Math.u_i-\frac{{\rho }_C}{\left({\rho }_O-{\rho }_C\right)}$

where C.sub.g is a specific heat of gas, C.sub.s is a specific heat of solid, G.sub.g is a flow rate of gas, G.sub.s is a flow rate of solid, ρ is a density of furnace top gas, in a unit of kg/m.sup.3, v is a descent velocity of the solid burden bed, in a unit of m/s, ρ.sub.O is a density of ore, in a unit of kg/m.sup.3, and ρ.sub.C is a density of coke, in a unit of kg/m.sup.3.

[0072] In the present application, the equation of the heat flow rate of solid within each of the temperature-measuring device regions is as follows:

[00005]${\left(C_s.Math.C_s\right)}_i={\left\{C_s.Math.\mathrm{vA}\left[{\rho }_O.Math.x+{\rho }_C\left(1-x\right)\right]\right\}}_i,.Math.x=\frac{L_O}{L_O+L_C};$

[0073] the equation of the heat flow rate of gas is (C.sub.g G.sub.g).sub.i=(C.sub.gρuS).sub.i;

wherein S is an area of the cross-section, through which the solid burden bed and the gas flow pass, within the temperature-measuring device region, and S.sub.i is the area of each of the temperature-measuring device regions, and in

[00006]$x=\frac{L_O}{L_O+L_C},$

Lo is an ore layer thickness, in a unit of meter, and Lc is a coke layer thickness, in a unit of meter.

[0074] In the present application, there are no particular limitations on the position of the burden material; the flowing direction of the three phases of solid, liquid and gas phases; and the process route within the blast furnace, which may be the operation situation of blast furnace well known to those skilled in the art. Reference may be specifically made to FIG. 3, which shows the position of burden material, the moving directions of the solid and gas, and the position where the on-line monitoring is performed within the blast furnace according to the present application.

[0075] In the present application, the thickness ratio of burden material layers within each of the temperature-measuring device regions is then acquired according to the pressure drop per unit length of burden layer (ΔP/L), the particle size distribution of materials and gas resistance equation of each lump zone of blast furnace, and then the function relation between the thickness ratio of burden material layers and the gas flow rate within each of the temperature-measuring device regions obtained in the above step is combined, to obtain the gas flow rate of each of the temperature-measuring device regions.

[0076] In the present application, for the convenience of subsequent calculation, the pressure drop per unit length of burden layer (ΔP/L) of the lump zone of blast furnace is preferably a preset value, and in the present application, there are no particular limitations on the presetting method of the ΔP/L, which may be a method well known to those skilled in the art, and is preferably set based on the total pressure drop of practical operation of blast furnace and the distance from the tuyere to the burden line according to the present application. The particle size distribution of materials (dp) of the lump zone of blast furnace, i.e., the particle size distribution of the coke and ore in the radial direction of blast furnace are preferably preset values, and in the present application, there are no particular limitations on the setting method of the particle size distribution of materials, which can be a method well known to those skilled in the art. In the present application, the particle size distribution of materials is preferably obtained by correlating with the throat radius, specifically, dp=f(r) (0≦r≦1), (r is a dimensionless throat radius), and its initial value is set as being uniformly distributed in the radial direction, i.e., dp=D.sub.p. In the present application, there are no particular limitations on the specific correlation method of the particle size distribution of materials in the blast furnace, which can be a measurement method for particle size distribution or distribution curve well known to those skilled in the art. In the present application, there are no particular limitations on the calculation method for the average particle diameter of the particles (D.sub.p), which can be a calculation method for the average particle diameter well known to those skilled in the art, and is preferably an arithmetical average method according to the present application.

[0077] The pressure drop per unit length of burden layer in each lump zone of blast furnace is preferably an value equal to each other, i.e.,

[00007]${\left(\frac{\Delta .Math..Math.P}{L}\right)}_1={\left(\frac{\Delta .Math..Math.P}{L}\right)}_2.Math..Math.\mathrm{.Math.}.Math..Math.{\left(\frac{\Delta .Math..Math.P}{L}\right)}_N;$

and the pressure drop per unit length of burden layer in each lump zone of blast furnace is preferably equal to the sum of a pressure drop per unit length of coke and a pressure drop per unit length of ore in said lump zone of blast furnace, that is,

[00008]${\left(\frac{\Delta .Math..Math.P}{L}\right)}_i={\left(\frac{\Delta .Math..Math.P}{L}\right)}_{O,i}.Math.x_i+{\left(\frac{\Delta .Math..Math.P}{L}\right)}_{C,i}.Math.\left(1-x_i\right).$

[0078] The gas resistance equation of each lump zone of blast furnace according to the present application is preferably:

[00009]${\left(\frac{\Delta .Math..Math.P}{L}\right)}_i={\left[k_1^{\star }.Math.\frac{{\left(1-\mathrm{.Math.}\right)}^2}{D_p^2.Math.{\mathrm{.Math.}}^3}.Math.\mathrm{\mu u}+k_2^{\star }.Math.\frac{\left(1-\mathrm{.Math.}\right)}{D_p.Math.{\mathrm{.Math.}}^3}.Math.\rho .Math..Math.u^2\right]}_i,$

wherein k.sub.1* is a viscous resistance coefficient, k.sub.2* is an inertia resistance coefficient, ΔP/L is a pressure drop per unit length, in a unit of kPa/m, ε is a burden bed porosity, D.sub.p is an average particle diameter of particles, in a unit of meter, μ is a gas viscosity, in a unit of Pa.Math.s, u is a gas flow rate, in a unit of m/s, and ρ is a gas density, in a unit of kg/m.sup.3.

[0079] In the present application, there are no particular limitations on the viscous resistance coefficient and the inertia resistance coefficient, which may be calculated by methods well known to those skilled in the art, and are preferably obtained in the present application according to the calculation method in “Distribution of Burden Materials and Gas permeability in a Large Volume Blast Furnace” published by Yamada (in kawasaki steel giho in 1974, 16-36), [0080] the viscous resistance coefficient and the inertia resistance coefficient of the coke are respectively:

k.sub.1*=450.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=2.2.Math.(D.sub.p.Math.10).sup.0.04; and [0081] the viscous resistance coefficient and the inertia resistance coefficient of the ore are respectively:

k.sub.1*=260.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=1.2.Math.(D.sub.p.Math.10).sup.0.04.

[0082] According to the present application, in combination with the above equations, under the given ΔP/L and the particle size distribution dp=f(r) (0≦r≦1) of coke and ore, the thickness ratio of burden material layers x.sub.1, x.sub.2, . . . , x.sub.N and the gas flow rate distribution u.sub.1, u.sub.2, . . . u.sub.N of each of the temperature-measuring device regions are finally obtained through calculation of above steps.

[0083] For purpose of ensuring the reliability of the calculated data and improving the accuracy of the calculated data, it is preferably according to the present application to verify the above calculated data. In the present application, there are no particular limitations on the method for the verification, which can be a method for verifying the above blast furnace data well known to those skilled in the art, and the verification according to the present application is preferably performed according to the following steps.

[0084] First, an average thickness ratio of burden material layers is calculated according to the thickness ratio of burden material layers within each of the temperature-measuring device regions, a total volume of gas flow passing through the temperature-measuring device regions is obtained according to gas flow rate in each of the temperature-measuring device regions, and a total heat of gas flow passing through the temperature-measuring device regions is further obtained.

[0085] Then, the average thickness ratio of burden material layers obtained in the above step is compared with a theoretical average thickness ratio of burden material layers, to obtain an error σ1; the total volume of gas flow passing through the temperature-measuring device regions obtained in the above step is compared with a theoretical total volume of furnace top gas flow, to obtain an error σ2; and the total heat of gas flow passing through the temperature-measuring device regions is compared with a theoretical total heat of furnace top gas flow, to obtain an error σ3.

[0086] Thereafter, an error analysis is made. The pressure drop per unit length of burden layer and the particle size distribution of burden materials are modified if one or more of the errors σ1, σ2, and σ3 has a value greater than or equal to 5%, and the step d) is performed again, until the value of each of the errors σ1, σ2, and σ3 is less than 5%; and the step e) is performed in the case that the value of each of the errors σ1, σ2, and σ3 is less than 5%.

[0087] In the present application, there are no particular limitations on the kinds of the detection date, which may be the kinds of detection date under normal states of blast furnace well known to those skilled in the art, and are preferably batch data of coke, batch data of ore, gas consumption, as well as composition, temperature, and pressure, or the like of various gases detected at the furnace top. In the present application, there are no particular limitations on the source of the detection date, which can be the source of detection date under normal states of blast furnace well known to those skilled in the art.

[0088] In the present application, the thickness ratio of burden material layers within each of the temperature-measuring device regions calculated by the above steps is firstly calculated to obtain the average thickness ratio of burden material layers; and then the total volume of gas flow passing through the temperature-measuring device regions is obtained according to the above gas flow rate of various temperature-measuring device regions, and the total heat of gas flow passing through the temperature-measuring device regions is in turn obtained. The above average thickness ratio of burden material layers, the total gas flow volume, and the total gas flow heat are all data obtained by calculation according to practical detection data and further through the above calculation method according to the present application.

[0089] The thickness ratio of burden material layers within each of the temperature-measuring device regions is preferably x.sub.i, the average thickness ratio of burden material layers is preferably X.sub.t, and the average thickness ratio of burden material layers is preferably calculated by the following formula:

[00010]$X_t=\underset{i=1}{\overset{N}{.Math.}}.Math.x_i.Math.S_i.Math.\text{/}.Math.A,$

wherein S.sub.i is an area of each of the temperature-measuring device regions, and A is a total area of the cross-section of blast furnace throat.

[0090] Regarding the total gas flow volume and total gas flow heat, preferably, the distributions of the gas volume V.sub.i and gas heat Q.sub.i at the furnace top are calculated according to the distribution of the gas flow rate u and then the volumes at various points are added together to obtain the total gas flow volume and total heat of gas flow,

V.sub.t=V.sub.1+V.sub.2+ . . . V.sub.N,Q.sub.t=Q.sub.1+Q.sub.2+ . . . Q.sub.N.

[0091] In the present application, the theoretical average ore-coke layer thickness ratio (i.e., the theoretical average thickness ratio of burden material layers) is further calculated according to the given batch data of coke and the given batch data of ore. Then, the volume V.sub.D of dry gas at the furnace top is calculated according to the N.sub.2 in the blast furnace gas by conservation law. According to the kinetics balance of reaction CO.sub.2+H.sub.2=H.sub.2O+CO at the furnace top, the volume V.sub.H2O of the water vapor at the furnace top is calculated, to thereby calculating the theoretical total furnace top gas flow volume V.sub.0 and the total furnace top gas heat Q.sub.0, i.e., the theoretical total gas flow volume at the furnace top and the theoretical total gas flow heat at the furnace top. The burden materials are preferably ore and coke, and the calculation formula of the theoretical average thickness ratio of burden material layers is preferably X.sub.0=[L.sub.O/(L.sub.O+L.sub.C)].sub.0, wherein Lo is a thickness of ore layer, and Lc is a thickness of coke layer. In the present application, there are no particular limitations on the calculation method of theoretical total gas flow volume at the furnace top and theoretical total gas flow heat at the furnace top, which can be calculation methods according to the kinetics balance equation of above reaction well known to those skilled in the art.

[0092] In the present application, the X.sub.t, V.sub.t and Q.sub.t calculated by the above calculation methods are compared with the theoretical values X.sub.0, V.sub.0 and Q.sub.0 obtained according to the above equations, to obtain errors σ1, σ2 and σ3. In the present application, there are no particular limitations on the calculation methods of the above errors, which can be calculation methods for errors well known to those skilled in the art. In the present application, there are no particular limitations on the verification scheme of the errors, which can be verification schemes or verification standards well known to those skilled in the art, and are preferably performed according to the following steps in the present application. In the case that any one of the above error values σ, σ2 and σ3 is greater than or equal to an error limit, the pressure drop per unit length of burden layer (ΔP/L) and the particle size distribution of burden materials (dp=f(r) (0≦r≦1)) are modified again, and the step for calculating the gas flow rate of various temperature-measuring device regions is performed again, until each of the numerical values of the error values σ1, σ2 and σ3 is less than the error limit; and in the case that the value of each of the error σ1, σ2 and σ3 is less than the error limit, the verification step is stopped. The error limit is preferably ranging from 3% to 7%, more preferably 4% to 6%, and most preferably 5%.

[0093] After the above verification step, if each of the error values is less than the error limit, the distribution of respective temperature-measuring device regions above and the gas flow rate thereof are plotted to obtain the detection result of the gas distribution.

[0094] The present application discloses a method for detecting a burden layer structure and gas flow distribution in a radial direction of blast furnace. The detection method disclosed in the present application is based on the main operation parameters of blast furnace such as blast condition, batch weight of coke and ore, pressure drop, furnace top gas composition and temperature, in which the throat is divided into several annular temperature-measuring device regions according to the temperature-measuring points of the cross-shaped temperature-measuring guns, and gas-solid heat balance and pressure loss of gas flow in the burden material layer in the several temperature-measuring device regions are calculated, to obtain the burden layer structure of the burden materials and the distribution of the gas flow (including velocity, volume and heat) in the radial direction of the throat, and verification and modification are made using mass balance of solid, mass balance of gas, and heat balance. The operator is allowed to obtain the change trends of the burden layer structure and radial distribution of gas flow by indirect means when the furnace conditions, such as the blast condition and the radial distribution form of the cross-shaped temperature-measuring guns, change, and to timely adjust the material distribution system of blast furnace, to thereby obtain a reasonable gas flow distribution, ensure the stable operation and extend the service life of blast furnace, and achieve the purpose of reducing the fuel ratio.

[0095] A system for detecting gas flow distribution in blast furnace is further provided according to the present application, which includes a division unit, a first attainment unit, an establishment unit, a second attainment unit, and a result unit, and preferably further includes a verification unit. The above units have one-to-one correspondence to the corresponding steps of the method for detecting gas flow distribution of blast furnace according to the present application. Since the detection method according to the present application has the above technical effects, the system for detecting gas flow distribution in blast furnace according to the present application also has the same technical effects.

[0096] With the detection method provided according to the present application, the heat flow ratio distribution, the ore layer thickness ratio distribution and the gas flow rate distribution at various points in the radial direction of blast furnace throat in various operational time periods are calculated, and the changes of respective parameters before and after each change of the burden distribution matrix are compared. The experimental results show that, the direction of each change of the burden distribution matrix is consistent with the direction of the change of the ore layer thickness ratio distribution calculated according to the present application, and changes in the gas flow distribution and the temperature distribution accordingly are also the same as expected.

[0097] For further illustrating the present application, the method for detecting gas flow distribution in blast furnace provided according to the present application is described in detail hereinafter with reference to examples, but the scope of the present application is not limited by the following examples.

Example 1

[0098] Firstly, in blast furnace with 2500 m.sup.3 in Hongfa plant of Shagang group, the number and position of the temperature measurement points of the cross-shaped temperature-measuring gun at the top of blast furnace were set, and the distance between the points was measured. One temperature-measuring gun was mounted in each of the four directions, i.e., east, south, west and north, of blast furnace throat, in which one temperature-measuring gun had six temperature-measuring points, and each of the other three temperature-measuring guns had five temperature-measuring points. A circle was drawn by taking the center of blast furnace as a center of the circle and taking the distances from the center of blast furnace to the middle of every two temperature-measuring points as a radius, and the cross-section of the throat was divided into six parts with areas thereof being S.sub.1, S.sub.2, S.sub.3, S.sub.4, S.sub.5 and S.sub.6, respectively. The distribution of areas S.sub.1 to S.sub.6 of respective temperature-measuring device regions was given in FIG. 4, which shows area of each region divided with the temperature-measuring device regions of the cross-shaped temperature-measuring guns according to Example 1 of the present application. The cross-shaped temperature-measuring guns was mounted to be inclined downwards by 15 degrees, and the temperature-measuring points were arranged equidistantly from the center to the edge, the space between every two cross-shaped temperature-measuring guns was 800 mm. The temperature points corresponding to the four temperature-measuring guns in the four directions were averaged, obtaining the diagram of the temperature distribution of the furnace top gas in the radial direction of the furnace throat. The above-mentioned arrangement is also shown in FIGS. 1 to 3.

[0099] Then, on-line detection was performed in the blast furnace, to obtain the detection numerical value. Reference is made to Table 1, which shows operating parameters of the on-line detection in the blast furnace.

TABLE-US-00001 TABLE 1 Operating parameters of the on-line detection in the blast furnace furnace furnace amount top top blast blast burden enriched of coke batch ore batch temperature pressure pressure capacity velocity oxygen coal (t/charge) (t/charge) (° C.) (kpa) (kpa) (Nm.sup.3/min) (Charge/h) (Nm.sup.3/h) (t/h) 11.883 69.41 21.27 207 363.1 4547.3 6.2474 17964 42.05 gas composition temperature distribution (° C.) CO(%) CO.sub.2(%) H.sub.2(%) N.sub.2(%) η.sub.CO(%) T1 T2 T3 T4 T5 T6 20.34 18.93 2.82 56.4 48.2 527 289 110 81.4 85.7 141.3

[0100] The temperature in the heat balance region was set at 1000° C. The model of the present application covers the heat balance from the top of blast furnace to the heat balance region, and ignores the heat loss caused by the chemical reaction of the lump zone, the heat exchange between the gas and the furnace wall, and the heat exchange between the solid and the furnace wall. According to the heat balance between gas and solid, that is, the heat of the gas is exactly transferred to the solid, it satisfies: C.sub.gG.sub.g (dT/dZ)=C.sub.sG.sub.s(alt/dZ), and each of radial temperature-measuring device regions meets the heat balance:

[00011]$\frac{C_s.Math.G_{s,i}}{C_g.Math.G_{g,i}}=\frac{\mathrm{dT}.Math.\text{/}.Math.\mathrm{dZ}}{\mathrm{dt}.Math.\text{/}.Math.\mathrm{dZ}}=\frac{\Delta .Math..Math.T}{\Delta .Math..Math.t}=\frac{1000-T_{g,i}\left(\mathrm{top}\right)}{1000-T_s\left(\mathrm{top}\right)},$

wherein T.sub.s(top)=25° C., T.sub.g,i(top) is the temperature value from on-line detection in each of temperature-measuring device regions. Based on the above relation, the solid-gas heat flow ratio C.sub.sG.sub.s/C.sub.gG.sub.g in each of the radial temperature-measuring device regions is calculated. As shown in Table 2, the numerical distributions of respective parameters are calculated according to Example 1 of the present application.

[0101] A function relation between the thickness ratio of burden material layers x.sub.i and the gas flow rate u.sub.i in each of the temperature-measuring device regions is established based on the solid-gas heat flow ratio,

[00012]$x_i={\left(\frac{C_s.Math.G_s}{C_g.Math.G_g}\right)}_i.Math.\frac{{\left(C_g\right)}_i.Math.{\left({\rho }_g\right)}_i}{C_s\left({\rho }_O-{\rho }_C\right).Math.v_i}.Math.u_i-\frac{{\rho }_C}{\left({\rho }_O-{\rho }_C\right)}$

wherein ρ.sub.O is the ore density, taking 2210 kg/m.sup.3, ρ.sub.C is the coke density, taking 500 kg/m.sup.3, L.sub.O is the ore layer thickness (m), L.sub.C is the coke layer thickness (m), and C.sub.s=1245 J/kg.Math.° C.

[0102] According to “Radial distribution of Burden Descent Velocity near Burden Surface in Blast Furnace”, published by ICHIDA in ISIJ international, Vol. 36 (1996), No. 5, pp. 493-502, the descent velocity of the burden is not uniform in the radial direction of blast furnace throat, and its radial descent velocity distribution is v=0.2259r+0.8529(0≦r≦1) (r is the dimensionless throat radius). Reference is made to FIG. 5, which is a diagram showing the radial descent velocity distribution of the burden in blast furnace in Example 1 of the present application. As in the radial direction, the gas flow temperature varies and the gas flow density may also vary accordingly, the gas flow density can be calculated according to

[00013]$\rho ={\rho }_0.Math.\frac{P}{P_0}.Math.\frac{T_0}{T},$

wherein ρ.sub.0, P.sub.0 and T.sub.0 are density, pressure and temperature of gas in a standard state, respectively; P and T are pressure and temperature in a working state, respectively, which are measured by an online instrument. As the gas flow temperature varies in the radial direction, the specific heat of the gas varies accordingly at various points in the radial direction. As have been pointed out in “Blast furnace iron-making production technical manuals”, the specific heat of the gas at various temperatures is Cp=a+bT+cT.sup.−2 (Jmol.sup.−1 K.sup.−1), and the coefficients a, b, and c are as shown in Table 3. Therefore, the average specific heat of respective temperature-measuring device regions is

[00014]${\stackrel{\_}{C}}_p=\frac{{\int }_{T_i}^{1000}.Math..Math.C_p.Math.\mathrm{dT}}{1000-T_i},$

assuming that the gas has the same composition at various points in the radial direction and the specific heat thereof only changes with the temperature, the specific heat of the gas at various points in the radial direction at the furnace top is

C.sub.p=α.sub.CO.Math.C.sub.p,CO+α.sub.CO.sub.2.Math.C.sub.p,CO2+α.sub.H.sub.2.Math.C.sub.p,H.sub.2.sub.O+α.sub.H.sub.2.sub.O.Math.C.sub.p,H.sub.2.sub.O+α.sub.N.sub.2.Math.C.sub.p,N.sub.2,

wherein α is the mass percentage of each gas component. As shown in Table 3, Table 3 is the mass percentage of each gas component in Example 1 of the present application.

[0103] Mass percentage of each gas component in Example 1 of the present application

TABLE-US-00002 applicable gas a b c temperature (K) CO 28.4 0.0041 −46000 298-2500 CO.sub.2 44.14 0.00904 −854000 298-2500 H.sub.2 27.3 0.0033 50000 298-3000 H.sub.2O 30 0.0107 33000 298-2500 N.sub.2 27.9 0.00427 0 298-2500

[0104] Finally, the distribution of the ore layer thickness ratio x.sub.i and the gas flow rate u.sub.i at various points in the radial direction of the cross-shaped temperature-measuring guns were calculated.

[0105] According to the function relation between the thickness ratio of burden material layers x.sub.i and the gas flow rate u

[00015]$\begin{array}{cc}{x}_i={\left(\frac{C_s.Math.G_s}{C_g.Math.G_g}\right)}_i.Math.\frac{{\left(C_g\right)}_i.Math.{\left({\rho }_g\right)}_i}{C_s\left({\rho }_O-{\rho }_C\right).Math.v_i}.Math.u_i-\frac{{\rho }_C}{\left({\rho }_O-{\rho }_C\right)},.Math.& 1.Math.◯\end{array}$

in the lump zone of blast furnace, the gas resistance equation is applied:

[00016]$\begin{array}{cc}\frac{\Delta .Math..Math.P}{L}=k_1^{\star }.Math.\frac{{\left(1-\mathrm{.Math.}\right)}^2}{D_p^2.Math.{\mathrm{.Math.}}^3}.Math.\mu .Math..Math.u+k_2^{\star }.Math.\frac{\left(1-\mathrm{.Math.}\right)}{D_p.Math.{\mathrm{.Math.}}^3}.Math.\rho .Math..Math.u^2,& 2.Math.◯\end{array}$

the pressure loss per unit length at each point is equal to the sum of the pressure losses per unit length of coke and ore:

[00017]$\begin{array}{cc}{\left(\frac{\Delta .Math..Math.P}{L}\right)}_i={\left(\frac{\Delta .Math..Math.P}{L}\right)}_{O,i}.Math.x_i+{\left(\frac{\Delta .Math..Math.P}{L}\right)}_{C,i}.Math.\left(1-x_i\right),& 3.Math.◯\end{array}$

and the pressure losses per unit length at each point is equal to each other in the lump zones:

[00018]$\begin{array}{cc}{\left(\frac{\Delta .Math..Math.P}{L}\right)}_1={\left(\frac{\Delta .Math..Math.P}{L}\right)}_2.Math.\mathrm{.Math.}.Math..Math.{\left(\frac{\Delta .Math..Math.P}{L}\right)}_6,& 4.Math.◯\end{array}$

wherein the porosity of the coke is 0.5, the porosity of the ore is 0.43, D.sub.p is the average particle diameter of the particles (m), the average particle diameter of the coke is 0.045 m, and the average diameter of the ore is 0.0173 m.

[0106] As the temperature of the gas flow varies in the radial direction, the gas viscosity also varies accordingly at various points in the radial direction, μ is the gas viscosity (Pa.Math.s), which is calculated according to the Sutherland formula:

[00019]$\mu =13.85\times {10}^{-6}.Math.\frac{T^{\frac{3}{2}}}{T+102},$

[0107] wherein T is the current gas temperature.

[0108] k.sub.1* is the viscous resistance coefficient, and k.sub.2* is the inertial resistance coefficient. For coke:

k.sub.1*=450.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=2.2.Math.(D.sub.p.Math.10).sup.0.04,

and for ore:

k.sub.1*=260.Math.(D.sub.p.Math.10).sup.0.84,k.sub.2*=1.2.Math.(D.sub.p.Math.10).sup.0.04.

[0109] It can be obtained by combining equations {circumflex over (1)}, {circumflex over (2)}, {circumflex over (3)} and {circumflex over (4)}:

a.sub.iut.sup.3+b.sub.iu.sup.2+c.sub.iu+d.sub.i=0  {circumflex over (5)},

wherein a.sub.i, b.sub.i, c.sub.i and d.sub.i are all the expressions in relation to x.sub.1, ε, D.sub.p,i, k.sub.1,i*, k.sub.2,i* it can be derived according to the above description that:

a.sub.i=f{x.sub.i,ε,D.sub.p,i,k.sub.1,i*,k.sub.2,i*,ΔP/L}; b.sub.i=g{x.sub.i,ε,D.sub.p,i,k.sub.1,i*,k.sub.2,i*,ΔP/L};

c.sub.i=h{x.sub.i,ε,D.sub.p,i,k.sub.1,i*,k.sub.2,i*,ΔP/L}; d.sub.i=k{x.sub.i,ε,D.sub.p,i,k.sub.1,i*,k.sub.2,i*,ΔP/L}.

[0110] According to the actual total pressure drop of blast furnace and the height from the tuyere to stock line of blast furnace, the initial value of ΔP/L was selected to be 0.77 Kpa/m, assuming that the coke and the ore have uniform particle size distribution in the radial direction of the furnace throat, a set of solutions can be given by solving equation {circumflex over (5)} under given conditions: the ore layer thickness ratio distribution x.sub.1, x.sub.2, . . . x.sub.6, and gas flow rate distribution u.sub.1, u.sub.2, . . . u.sub.6. As shown in Table 2, Table 2 shows the numerical distributions of respective parameters calculated in Example 1 of the present application.

Verification Step

[0111] (1) The theoretical average thickness ratio of burden material layers at the furnace top, the theoretical total furnace top gas flow volume V.sub.0 and the theoretical total furnace top gas flow heat Q.sub.0 were calculated.

[0112] According to the solid consumption, the gas consumption, the gas composition detected at the furnace top and the furnace top temperature given in Table 1, the batch weight of coke given as 12.2 t, and the batch weight of ore given as 71 t, the average burden layer structure was calculated to be X.sub.0=[L.sub.O/(L.sub.O+L.sub.C)].sub.0=0.569; the blast condition of the tuyere area was as follows: blast volume of 4547 Nm.sup.3/min, enriched oxygen of 17964 Nm.sup.3/h, and pulverized coal injection of 42.05 t/h; the gas composition detected by the furnace top on-line gas analyzer was as follows: CO: 20.34%, CO.sub.2: 18.93%, H.sub.2: 2.82%, N.sub.2: 56.4%; gas pressure P.sub.top=207 kPa, gas temperature T.sub.top=121.27° C. The volume of N.sub.2 introduced through the tuyere was:

V.sub.N2=BV.Math.0.79+N.sub.2coal/60+PCI/60.Math.1000.Math.N.sub.PCI.Math.22.4/28,

wherein BV was the cold-blast volume, in a unit of Nm.sup.3/min; N.sub.2coal was the flow rate of carrier gas N.sub.2 of pulverized coal, in a unit of Nm.sup.3/h; PCI was the amount of pulverized coal injection, in a unit of t/h; and N.sub.PCI was the content of N in the pulverized coal.

[0113] According to the equilibrium of N.sub.2, the total volume of dry gas at the furnace top can be calculated as V.sub.D=V.sub.N.sub.2/(N.sub.2%)=6047.4 Nm.sup.3/min, the reaction of water vapor at the furnace top at 450° C. is CO+H.sub.2O=CO.sub.2+H.sub.2, and a reaction equilibrium constant is K=p.sub.H.sub.2.Math.p.sub.CO.sub.2/p.sub.CO.Math.P.sub.H.sub.2.sub.O=4.5, the water vapor at the furnace top can be calculated as V.sub.H2O=63.5 Nm.sup.3/min, the total volume of furnace top gas can be calculated as V.sub.0=V.sub.D+V.sub.H2O=6110.9 Nm.sup.3/min; and the total heat of furnace top gas can be calculated as Q.sub.0=C.sub.p.Math.V.sub.0.Math.(T.sub.top−25)=828714 KJ/min.

[0114] (2) The average thickness ratio of burden material layers X.sub.t was calculated according to the thickness ratio of burden material layers of the temperature-measuring device regions calculated by the above method in Table 2; the total volume V.sub.i of the gas flow passing through the temperature-measuring device regions was obtained according to the above gas flow rate of each of the temperature-measuring device regions in Table 2, and the total heat Q.sub.i of the gas flow passing through the temperature-measuring device regions was thus obtained. The values of above V.sub.i and Q.sub.i are shown in Table 2, and Table 2 shows the numerical distributions of respective parameters calculated in Example 1 of the present application.

[0115] Regarding the average thickness ratio of burden material layers

[00020]$X_t=\underset{i=1}{\overset{6}{.Math.}}.Math.x_i.Math.S_i.Math.\text{/}.Math.A,$

A was the total area 54.1 m.sup.2 of the throat cross-section; the volume of gas passing through each point can be obtained according to the calculated gas velocity u.sub.i: V.sub.i=u.sub.i.Math.S.sub.i(i=1 . . . 6). The total volume of gas flow can be obtained by adding the volumes of the gas at respective points V.sub.t=V.sub.1+V.sub.2+V.sub.6. Similarly, by accumulating Q.sub.i=C.sub.p.Math.V.sub.i.Math.[T.sub.i(top)−25](i=1 . . . 6) at each point, the total gas heat Q.sub.t=Q.sub.1+Q.sub.2+ . . . Q.sub.6 was obtained.

TABLE-US-00003 TABLE 2 the numerical distribution of respective parameters calculated in Example 1 of the present application calculated parameters 1 2 3 4 5 6 (CsGs/CgGg).sub.i 0.4855 0.7296 0.9128 0.9422 0.9378 0.8807 x.sub.i 0.1269 0.3664 0.6307 0.6628 0.6142 0.4995 u.sub.i 1.328 1.042 0.8457 0.8228 0.8466 0.9241 V.sub.i 41.73 372.6 887 1399 1897 1492 Q.sub.i 31560 142600 106400 110800 161800 246100

[0116] (3) Verification of Data

[0117] The theoretical burden material layer structure X.sub.0 was calculated by the calculated batch weight of ore and coke. The theoretical total furnace top gas flow volume V.sub.0 and the theoretical total furnace top gas flow heat Q.sub.0 had been calculated by the above equilibrium of N.sub.2. X.sub.t, V.sub.t, and Q.sub.t were compared with X.sub.0, V.sub.0 and Q.sub.0 respectively, and the errors σ.sub.1, σ.sub.2 and σ.sub.3 were set as the error σ.sub.t=[X.sub.t−X.sub.0]/X.sub.0, σ.sub.2=(V.sub.t−V.sub.0)/V.sub.0, and σ.sub.3=(Q.sub.t−Q.sub.0)/Q.sub.0 (0<σ.sub.1, σ.sub.2, σ.sub.3<5%). If the errors σ.sub.1, σ.sub.2 and σ.sub.3 exceeded above ranges, the ΔP/L was modified, and the thickness ratio of burden material layers x.sub.1, x.sub.2, . . . x.sub.6 and the gas flow rate u.sub.1, u.sub.2, . . . u.sub.6 were recalculated, until the errors were in the selected ranges. When ΔP/L=1.545 kpa/m finally, the calculation was stopped, and the final distribution of respective parameters in the radial direction of blast furnace throat was obtained. As shown in Table 3, Table 3 shows a comparative analysis of the parameters calculated in Example 1 of the present application and the parameters calculated theoretically.

TABLE-US-00004 TABLE 3 Comparative analysis of the parameters calculated in Example 1 of the present application and the parameters calculated theoretically Convergence X.sub.t 0.5761 X.sub.0 0.5692 ΔX 0.012122 V.sub.t 6090 V.sub.0 6111 ΔV −0.00344 Q.sub.t 799200 Q.sub.0 828700 ΔQ −0.0356

Example 2

Verification of the Burden Layer Structure and Gas Flow Rate Distribution Detection in Practical Blast Furnace Operation

[0118] In blast furnace 1# from Hongfa plant of Shagang group, during the period from Dec. 1, 2013 to Jan. 20, 2014, the quality of the raw material in the blast furnace was deteriorated, the slag ratio was increased to 320 kg/t-HM, and M40 was reduced from 84 to 81. Although the raw material conditions were deteriorated, the operator allows the pressure drop of blast furnace to decrease through adjustment of the burden distribution matrix and the gas utilization rate was improved. Reference is made to FIG. 6, which shows the operation condition of blast furnace with 2500 m.sup.3 in Hongfa plant according to the present application from the end of 2013 to the beginning of 2014, as shown in FIG. 6. The main operating parameters vary from Case 1 to Case 5, and the specific parameters are as shown in Table 4.

TABLE-US-00005 TABLE 4 Change of main operating parameters of blast furnace with 2500 m.sup.3 in Hongfa plant from December 2013 to January 2014 gas composition temperature distribution pressure operating CO CO.sub.2 H.sub.2 N.sub.2 η.sub.CO T1 T2 T3 T4 T5 T6 drop interval (%) (%) (%) (%) (%) (° C.) (° C.) (° C.) (° C.) (° C.) (° C.) (Kpa) case 1 20.34 18.93 2.82 56.4 48.2 527 289 110 81.4 85.7 141.3 156.1 (Dec. 1, 2013 to Dec. 6, 2013) case 2 20.76 18.98 2.77 55.99 47.76 638.6 314 110 80.3 77.6 100.5 155.6 (Dec. 7, 2013 to Dec. 17, 2013) case 3 21.1 18.9 2.58 55.89 47.2 632.3 290.5 99.1 78.8 78.9 92.8 150.3 (Dec. 18, 2013 to Dec. 25, 2013) case 4 19.96 18.5 2.48 57.56 48.1 539 240 102 81.4 80 91.5 152 (Dec. 26, 2013 to Jan. 2, 2014) case 5 19.8 18.74 2.482 57.48 48.62 478 206.7 91.6 73.2 70.1 73.8 152.7 (Jan. 3, 2014 to Jan. 20, 2014)

[0119] Based on these five operating periods, the heat flow ratio distribution, thickness ratio of burden material layers distribution and gas flow rate distribution of respective temperature-measuring device regions in the radial direction of blast furnace throat within these five time periods were respectively calculated, and the changes of respective parameters before and after each change of the burden distribution matrix were compared. It is found that, the direction of each change of the burden distribution matrix is consistent with the direction of the distribution change of the ore layer thickness ratio calculated, and changes in the gas flow distribution and the temperature distribution accordingly are also the same as expected.

[0120] Specific analysis: reference is made to FIG. 7, which shows the change of respective parameters from Case 1 to Case 2 according to the present application. As shown in FIG. 7, from Case 1 to Case 2, the operator changes the burden distribution matrix from C.sub.33222212.sup.109876531O.sub.14443.sup.98765 to C.sub.23222222.sup.109876543O.sub.24443.sup.98765 wherein for C.sub.b.sup.a, C is the charge item of coke in the burden distribution matrix, a is the charging position, and b is the number of turns; for O.sub.b.sup.a, O is the charge item of ore in the burden distribution matrix, a is the charging position and b is the number of turns. Charging position 10 is close to the furnace wall, charging position 1 is the center of blast furnace, charging position 9 at an edge of the ore is changed from one turn to two turns. It can be inferred that, the ore layer thickness ratio at the edge increases and the gas flow rate at the edge decreases, which are consistent with the directions of distribution change of the calculated ore layer thickness ratio X.sub.1 and the calculated gas flow rate

[0121] Reference is made to FIG. 8, which shows the change of respective parameters from Case 2 to Case 3 according to the present application. As shown in FIG. 8, from Case 2 to Case 3, M40 is decreased significantly, the slag ratio is increased rapidly, the operator changes the burden distribution matrix from C.sub.23222222.sup.109876543O.sub.24443.sup.98765 to C.sub.3222222.sup.10987654O.sub.24443.sup.98765, 2 turns of coke is removed from the charging position 3. It can be inferred that, the coke in the corresponding middle part is increased and the layer thickness ratio of the ore is decreased, which are consistent with the change of the distribution of the calculated ore layer thickness ratio x.sub.i.

[0122] Reference is made to FIG. 9, which shows the change of respective parameters from Case 3 to Case 4 according to the present application. As shown in FIG. 9, from Case 3 to Case 4, the operator changes the burden distribution matrix from C.sub.3222222.sup.10987654O.sub.24443.sup.98765 to C.sub.2222222.sup.10987654O.sub.2233332.sup.10987654, charging position 10 and charging position 4 of the ore are each provided with two turns. It can be inferred that, the ore layer thickness ratios of the center part and the center part are increased and the ore layer thickness ratio of the middle part is reduced, which are basically consistent with the calculated results.

[0123] Reference is made to FIG. 10, which shows the change of respective parameters from Case 3 to Case 4 according to the present application. As shown in FIG. 10, from Case 4 to Case 5, the operator changes the burden distribution matrix from C.sub.2222222.sup.10987654O.sub.2233332.sup.10987654 to C.sub.2233322.sup.10987654O.sub.3233332.sup.10987654, the intermediate charging positions “6”, “7” and “8” of coke change from being provided with two turns to three turns. The ore layer thickness ratio at the corresponding middle part is reduced, which is consistent with the calculated result. In addition, charging position 10 of the ore changes from being provided with two turns to three turns, the ore layer thickness ratio at the corresponding edge is inferred to be increased, which is consistent with the calculated result.

[0124] From the above analysis, it can be seen that the accuracy of the method for detecting the gas flow distribution and the radial ore layer thickness radio in blast furnace according to the present application demonstrates the merit of this method for guiding the practical blast furnace operation.

[0125] The method for detecting gas flow distribution in blast furnace provided according to the present application has been described in detail hereinbefore. The principle and the embodiments of the present application are illustrated herein by specific examples. The above description of examples is only intended to help the understanding of the method according to the present application and the core spirit thereof. It should be noted that, for those skilled in the art, several modifications and improvements may be made to the present application without departing from the principle of the present application, and these modifications and improvements are also deemed to fall within the scope of the present application defined by the claims.