Apparatus, method, and program for detecting molten metal surface level in continuous casting mold

Patent metadata

Field	Value
Publication number	US-10583477-B2
Application number	US-201515519328-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 15, 2014
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A heat flux derivation unit (202) derives a value qy of a y-axis direction component of a heat flux vector. A molten metal surface level derivation unit (203) derives, as a molten metal surface level, a position where the absolute value of the value qy of the y-axis direction component of the heat flux vector whose y-axis component vector is in a direction opposite to a casting direction is maximum.

First claim

The invention claimed is:

1. An apparatus for detecting a molten metal surface level in a continuous casting mold, the apparatus comprising:
a computer processor including processing circuitry programmed to perform operations comprising:
acquiring temperatures measured by a plurality of temperature measurement devices embedded in the continuous casting mold along a casting direction of the continuous casting mold;
deriving a value of a casting direction component of a heat flux vector on an inner wall surface of the continuous casting mold, based on a result of performing analysis of non-stationary heat conduction inverse problems from the temperatures acquired by the computer processor; and
deriving a molten metal surface level inside the continuous casting mold, based on the value of the casting direction component of the heat flux vector on the inner wall surface of the continuous casting mold derived by the computer processor,
wherein the computer processor is programmed to derive, as the molten metal surface level, a position where an absolute value of the value of the casting direction component of the heat flux vector whose vector of the casting direction component is in a direction opposite to the casting direction is maximum.

2. The apparatus for detecting the molten metal surface level in the continuous casting mold according to claim 1 ,
wherein the analysis of non-stationary heat conduction inverse problems is analysis of non-stationary heat conduction inverse problems using an interpolation/extrapolation temperature function satisfying a non-stationary heat conduction equation, and
wherein the interpolation/extrapolation temperature function is a function u{circumflex over ( )}(x, y, t) indicating a temperature inside the continuous casting mold at a position x in an x-axis direction being a heat removal direction of the continuous casting mold, a position y in a y-axis direction being the casting direction of the continuous casting mold, and a time t.

3. The apparatus for detecting the molten metal surface level in the continuous casting mold according to claim 2 ,
wherein the interpolation/extrapolation temperature function u{circumflex over ( )}(x, y, t) is expressed by a total sum of values at respective center points j of products of a basis function ϕ j decided for each center point j and a weight vector λ j decided for each center point j,
wherein the center point j is a point decided by a reference position vector (x j , y j ) indicating a position that is a reference in the x-axis direction and the y-axis direction of the continuous casting mold and a reference time t j , which is a point on three-dimensional coordinates decided by positions in the x-axis direction and the y-axis direction of the continuous casting mold and a time, and
wherein the basis function ϕ j is a function expressed in a form of a fundamental solution satisfying the non-stationary heat conduction equation based on the center point j.

4. The apparatus for detecting the molten metal surface level in the continuous casting mold according to claim 3 ,
wherein the computer processor derives a value q y of a y-axis direction component of the heat flux vector on the inner wall surface of the continuous casting mold by a following (A) expression,
where following β is a heat conductivity of a material constituting the continuous casting mold,
following a is a square root of a thermal diffusion coefficient of the material constituting the continuous casting mold,
following H(t−t j ) is a Heaviside function, and
following m+1 is a number of the center points j,

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Assignees

• Nippon Steel & Sumitomo Metal Corp
• Nippon Steel Corp

Inventors

• Nakagawa Junichi
• Hiramoto Yuuji

Classifications

• B22D11/182 Primary

  by measuring temperature · CPC title

• B22D11/041

  for vertical casting (B22D11/043, B22D11/049 - B22D11/059 take precedence) · CPC title

• G01F23/22

  by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water (involving the use of floats G01F23/30) · CPC title

• B22D11/181 Primary

  responsive to molten metal level or slag level · CPC title