CN-121997597-A - Design method of scrap steel composition for converter steelmaking

CN121997597ACN 121997597 ACN121997597 ACN 121997597ACN-121997597-A

Abstract

The invention discloses a design method of scrap steel composition for converter steelmaking, which comprises the steps of determining a factor influencing smelting cost as an independent variable, designing a test scheme by adopting a quadratic regression orthogonal combination design method, wherein the cost is a dependent variable. And executing cost accounting on the test scheme, and obtaining a quadratic regression equation reflecting the relation between the respective variables and the cost by adopting least square fitting based on the cost data. And performing analysis of variance and significance test on the quadratic regression equation, and determining key factors and non-key factors which have significant influence on the cost. And fixing the value of a non-key factor, analyzing the influence of the key factor on the cost, and determining the optimal scrap steel proportioning scheme. The invention realizes the fundamental transition of converter ingredients from 'experience dependence' to 'model driving' and from 'local optimization' to 'global optimization' through systematic experimental design, mathematical model and statistical analysis and layered optimization strategy, thereby achieving the minimization of steelmaking cost.

Inventors

WEN YAWEI
ZOU HAILI
ZHANG GELIANG
SUN WEI
LUO DEHONG
XIA XUHE

Assignees

资环链金再生资源有限公司

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (8)

1. The design method of the scrap steel composition for converter steelmaking is characterized by comprising the following steps of: S1, determining a factor affecting smelting cost as an independent variable, designing an experimental scheme by adopting a quadratic regression orthogonal combination design method, wherein the cost is a dependent variable; S2, executing a cost accounting step on the experimental scheme in S1, adopting least square fitting to obtain a quadratic regression equation reflecting the relation between the respective variables and the cost based on the cost data, setting a quadratic term x j 2 in the quadratic regression equation, and representing the corresponding code by x ij 2 , wherein the quadratic term centering processing formula is as follows: x ij =x ij 2 -0.843, then according to coding formula Performing back substitution to obtain natural variable A regression equation for the steel cost y t , wherein, In order to encode the symbol, In order to vary the spacing between the two, As natural variable codes, along with the change of the molten iron cost, different regression equations about the steel material cost t are obtained, the influence rule of a certain scrap type on the steel material cost is researched by changing the levels of all factors in the regression equations, the other factors are all zero levels, and the influence rule of the addition of different types of scrap steel on the steel material cost is analyzed; S3, performing analysis of variance and significance test on the quadratic regression equation in the S2, wherein the analysis of variance is available, and along with the change of the molten iron cost, the influences of all factors, namely the scrap steel types, on the steel material cost are orderly sequenced from large to small, and the key factors and the non-key factors which have obvious influence on the cost are determined, wherein the key factors and the non-key factors refer to the scrap steel types; And S4, fixing the value of a non-key factor, taking the zero level of other factors, analyzing the influence of the key factor on the cost, and determining the scrap steel proportioning scheme with the optimal cost.
2. The method of claim 1, wherein S1 is a steel scrap type, molten iron and pig iron addition, and wherein the steel scrap type is any combination of heavy-duty steel scraps, sheared steel scraps, packed steel scraps, crushed materials, bar ends and light and thin materials.
3. The method for designing a scrap steel feed for use in converter steelmaking as set forth in claim 2, wherein when the argument in S1 is a scrap steel type, the range of addition of the different scrap steel types is determined based on the molten iron composition, the scrap steel type, the impurity content, the price, the scrap steel loading amount, the tapping amount, and the empirical addition in production practice.
4. The method for designing a scrap steel composition for converter steelmaking according to claim 1, wherein the cost accounting step in S2 is as follows: S201, carrying out material balance and heat balance calculation on converter steelmaking by using an EXCEL calculation table on the experimental scheme designed in the S1; S202, judging the surplus heat of the system according to the heat balance calculation result, enabling the surplus heat to be close to zero by adjusting the addition amount of the independent variables, and inputting the values of various independent variables under the scheme; And S203, based on the values of various independent variables, checking the unit price of the independent variables and calculating the cost.
5. The method for designing the scrap steel feed for converter steelmaking, as set forth in claim 1, wherein the step S3 of checking the significance is F-checking, specifically includes calculating the F value of each regression coefficient, comparing the F value with the F critical value to determine whether the F value is significant at the alpha=0.01 level, and determining the order of magnitude of the influence of each scrap steel on the cost by comparing the F value of each regression coefficient of each factor, thereby determining the significance of each variable.
6. A method of designing a scrap steel composition for converter steelmaking as set forth in claim 1 wherein the cost optimized scrap steel proportioning scheme in S4 is determined based on either an independent variable cost minimization or a total cost minimization.
7. A method of designing a scrap steel feed for converter steelmaking in accordance with claim 6 wherein the total cost is the sum of the cost of the independent variables, the cost of the slag former and the cost of oxygen consumption.
8. The method for designing a scrap steel composition for converter steelmaking of claim 1 further comprising predicting a cost of smelting at a specified scrap steel ratio by regression equation to provide real-time data support for production decisions.

Description

Design method of scrap steel composition for converter steelmaking Technical Field The invention relates to the technical field of steel manufacturing, in particular to a design method of scrap steel composition for converter steelmaking. Background Scrap steel is one of main metal materials in converter steelmaking, can provide iron-containing raw materials, and is a coolant with stable cooling effect. The steel scrap ratio is properly increased, so that the converter steelmaking cost can be reduced. The sources of the scrap steel are different, the scrap steel of different types of enterprises has larger differences in impurities, elements, quality and the like, and difficulties are brought to the classification and benefit evaluation of the scrap steel, so that when the scrap steel is used by each steel enterprise, the scrap steel is generally proportioned by adopting simple material balance and heat balance. In the conventional converter steelmaking production, the addition amount of scrap steel is generally calculated according to the heat balance of furnace burden, and the total amount of scrap steel is empirically proposed by combining the conditions of molten iron temperature, components and the like and fed back to a charging process, so that the specific proportioning relation among different types of scrap steel is not generally defined. In actual operation, the proportion of various types of scrap steel depends on manual experience or historical charging habit, a scientific calculation model is lacked, and the cost change of different scrap steel proportions is not considered. The empirical batching mode is easy to cause the problems of unstable heat balance in the furnace, insufficient melting of partial scrap steel, deviation of terminal temperature, waste of cost and the like when the fluctuation of molten iron components is large or the production rhythm is changed. Aiming at the problems, the prior art only provides charging sequence, charging proportion and the like, but does not relate to specific proportion sources of different types of scrap steel proportions, lacks scientific data support, does not have influences on smelting metallurgical effects such as iron and steel materials, slag quantity, slag forming agents and oxygen consumption after the different types of scrap steel proportions, cannot embody complex nonlinear relation and interaction effects existing between the scrap steel proportions and the cost of the iron and steel materials, and the decision is mostly dependent on experience or simple linear assumption, so that the proportion scheme cannot approach to theoretical optimal solution, and does not have contribution to cost and regression analysis after the scrap steel proportions. Disclosure of Invention The invention aims to provide a design method of scrap steel composition for converter steelmaking, which realizes the fundamental transition of converter ingredients from 'experience dependence' to 'model driving' and from 'local optimization' to 'global optimization' through systematic experimental design, mathematical model and statistical analysis and layering optimization strategy, thereby achieving the minimization of steelmaking cost and solving the defects of the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: a design method of scrap steel composition for converter steelmaking comprises the following steps: S1, determining a factor affecting smelting cost as an independent variable, designing an experimental scheme by adopting a quadratic regression orthogonal combination design method, wherein the cost is a dependent variable; S2, executing a cost accounting step on the experimental scheme in S1, adopting least square fitting to obtain a quadratic regression equation reflecting the relation between the respective variables and the cost based on the cost data, setting a quadratic term x j2 in the quadratic regression equation, and representing the corresponding code by x ij2, wherein the quadratic term centering processing formula is as follows: x ij=xij2 -0.843, then according to coding formula Performing back substitution to obtain natural variableA regression equation for the steel cost y t, wherein,In order to encode the symbol,In order to vary the spacing between the two,As natural variable codes, along with the change of the molten iron cost, different regression equations about the steel material cost t are obtained, the influence rule of a certain scrap type on the steel material cost is researched by changing the levels of all factors in the regression equations, the other factors are all zero levels, and the influence rule of the addition of different types of scrap steel on the steel material cost is analyzed; S3, performing analysis of variance and significance test on the quadratic regression equation in the S2, wherein the analysis of variance is available, and along with the chang