JP6428419B2

JP6428419B2 - Method, apparatus and program for controlling flow rate of molten steel in continuous casting mold

Info

Publication number: JP6428419B2
Application number: JP2015057614A
Authority: JP
Inventors: 平本　祐二; 祐二平本; 中川　淳一; 淳一中川; 隆史奥村
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2015-03-20
Filing date: 2015-03-20
Publication date: 2018-11-28
Anticipated expiration: 2035-03-20
Also published as: JP2016175107A

Description

本発明は、連続鋳造鋳型（モールド）内の溶鋼流量制御方法、装置及びプログラムに関する。 The present invention relates to a molten steel flow rate control method, apparatus, and program in a continuous casting mold.

連続鋳造操業においては、安定鋳造（ブレイクアウト等の鋳造トラブルの防止）や鋳片品質確保の観点から、鋳型内の湯面レベルの検出精度の向上が極めて重要である。例えば浸漬ノズルパウダーラインの局部的な溶損を防止するために、鋳造中の一定時間経過ごとに浸漬ノズルの浸漬深さを変更することが行われているが、湯面レベルの検出精度が悪いと、溶鋼流量制御が適正に行われなくなる。そのため、湯面位置の制御精度が悪くなって浸漬ノズルの浸漬深さ変更が不十分となる場合があり、局部溶損の助長、さらにはノズルへの孔開きにより空気が侵入して溶鋼の空気酸化、品質低下を引き起こす場合がある。 In continuous casting operations, it is extremely important to improve the detection accuracy of the molten metal surface level in the mold from the viewpoints of stable casting (preventing casting troubles such as breakout) and slab quality. For example, in order to prevent local melting of the immersion nozzle powder line, the immersion depth of the immersion nozzle is changed every time a certain time elapses during casting, but the detection accuracy of the molten metal level is poor. Then, the molten steel flow rate control is not properly performed. As a result, the control accuracy of the molten metal surface may be deteriorated and the immersion depth of the immersion nozzle may not be changed sufficiently. It may cause oxidation and quality degradation.

鋳型内の湯面を検出する手段としては、渦流式湯面計が一般に用いられているが、渦流式湯面計は鋳型内の導電体の影響を受けやすく、出力特性が変化し易いため、検出精度が高いとはいえない。例えば特許文献１に、鋳型短辺からの影響を受けない位置における湯面と渦流式センサー間の電圧特性を基準として、センサー特性を補正する技術が開示されている。
また、特許文献２には、鋳型壁の高さ方向に沿って等間隔に複数個の測温素子を埋設し、任意周期毎に各素子の点における温度の時間変化率値を演算し、該時間変化率の最大値を示す素子（ｎ）を検出し、該素子（ｎ）とその前後の素子（ｎ−１）、（ｎ＋１）の各時間変化率値を結ぶ二次曲線の最大値を示す位置を求め、該位置を湯面レベルとする技術が開示されている。
また、特許文献３には、鋳造方向に間隔をおいて鋳型の複数箇所に埋設した温度計測手段で鋳型温度を計測し、鋳型温度計測値に基づいて各計測点における鋳型内面での熱流束を伝熱逆問題手法を用いてそれぞれ推定する技術が開示されている。 As a means for detecting the molten metal level in the mold, the eddy current type liquid level gauge is generally used, but the eddy current type water level gauge is easily affected by the conductor in the mold, and the output characteristics are likely to change. It cannot be said that the detection accuracy is high. For example, Patent Document 1 discloses a technique for correcting sensor characteristics on the basis of voltage characteristics between a molten metal surface and an eddy current sensor at a position not affected by the short side of the mold.
Further, Patent Document 2 embeds a plurality of temperature measuring elements at equal intervals along the height direction of the mold wall, calculates the time change rate value of the temperature at each element point for each arbitrary period, The element (n) showing the maximum value of the time change rate is detected, and the maximum value of the quadratic curve connecting the time change rate values of the element (n) and the preceding and following elements (n−1) and (n + 1) is obtained. A technique for obtaining a position to be shown and setting the position to a hot water level is disclosed.
In Patent Document 3, the mold temperature is measured by temperature measuring means embedded in a plurality of locations of the mold at intervals in the casting direction, and the heat flux on the inner surface of the mold at each measurement point is calculated based on the measured mold temperature. A technique for estimating each using the inverse heat transfer problem method is disclosed.

特開２０１３−１６６１６７号公報JP 2013-166167 A 特開昭５３−２６２３０号公報JP-A-53-26230 特開２００１−２３９３５３号公報JP 2001-239353 A

しかしながら、特許文献１に記載のセンサー特性を補正する方式を用いても、導電性を帯びた周辺設備の改造等によりセンサー特性が変化するために、測定された湯面レベルの絶対値の信頼性が低い。そのため、鋳造時に何らかの手段で湯面の絶対値を計測して補正することが行われている。例えば溶鋼より融点が低い銅線を溶鋼に浸漬して鋳型上端と湯面との距離を計測して補正する等の方法が実施されている。しかしながら、銅線浸漬後、引き上げて残存した銅線長さと渦流式湯面計の値との比較から補正値を入力する間に、実際の湯面は変化してしまうことがあり、補正後の湯面の絶対値の信頼性が担保されていなかった。その結果、精度よく湯面位置を制御することができず、渦流式湯面計の値は鋳造チャンスごとに湯面レベルは±２０ｍｍ程度ずれることがあり、鋳造トラブルリスクを回避することが困難であった。 However, even if the method for correcting the sensor characteristics described in Patent Document 1 is used, the sensor characteristics change due to modification of peripheral equipment with conductivity, etc., so the reliability of the absolute value of the measured hot water surface level is high. Is low. Therefore, the absolute value of the molten metal surface is measured and corrected by some means during casting. For example, a method has been implemented in which a copper wire having a melting point lower than that of molten steel is immersed in molten steel and the distance between the upper end of the mold and the molten metal surface is measured and corrected. However, the actual molten metal surface may change while the correction value is input from the comparison between the length of the copper wire pulled up and remaining after the copper wire immersion and the value of the eddy current type water surface meter. The reliability of the absolute value of the hot water surface was not guaranteed. As a result, the position of the hot water surface cannot be accurately controlled, and the value of the eddy current type water surface meter may be shifted by about ± 20 mm at every casting chance, making it difficult to avoid the risk of casting trouble. there were.

また、特許文献２に代表される既存の手法は、鋳型の鋳造方向の温度が最大となる位置が湯面近傍にあり、湯面位置とある相関があるという経験則に基づくものである。このように経験則に基づく場合、湯面レベルの検出精度が低いものとなってしまう懸念がある。具体的には、鋳型に埋設された熱電対の温度変化率は溶鋼温度や湯面変化速度によって左右され、溶鋼温度が高いほど温度変化率が大きくなり、また湯面変化速度が大きいと鋳型の温度上昇の時間遅れにより湯面位置の検出遅れが大きくなるという問題がある。 Moreover, the existing method represented by patent document 2 is based on the empirical rule that the position where the temperature in the casting direction of the mold is maximum is in the vicinity of the molten metal surface and has a certain correlation with the molten metal surface position. Thus, when based on an empirical rule, there exists a possibility that the detection accuracy of a hot-water surface level may become low. Specifically, the temperature change rate of the thermocouple embedded in the mold depends on the molten steel temperature and the molten steel surface change rate. The higher the molten steel temperature, the greater the temperature change rate. There is a problem that the detection delay of the hot water surface position becomes large due to the time delay of the temperature rise.

特許文献３は、熱流束を伝熱逆問題を用いて推定する方法であるが、熱流束と湯面レベル、溶鋼流量制御についての記述はない。 Patent Document 3 is a method of estimating the heat flux using the inverse heat transfer problem, but there is no description about the heat flux, the molten metal surface level, and the molten steel flow rate control.

本発明は上記のような点に鑑みてなされたものであり、湯面位置における熱移動の影響を捉えて湯面レベルを検出することにより湯面レベルの検出精度を高め、溶鋼流量制御を高精度化して、安定操業を実現することを目的とする。 The present invention has been made in view of the above points, and by detecting the level of the molten metal level by detecting the influence of heat transfer at the level of the molten metal level, the detection accuracy of the molten metal level is improved and the molten steel flow rate control is enhanced. The purpose is to improve accuracy and achieve stable operation.

上記課題を解決するための、本発明は以下のとおりである。
［１］連続鋳造鋳型内の溶鋼流量を制御する溶鋼流量制御方法であって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を取得する取得ステップと、
前記取得ステップで取得した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算ステップと、
前記計算ステップで計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出ステップと、
前記湯面レベル検出ステップで検出した湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御ステップとを有し、
前記湯面レベル検出ステップでは、前記計算ステップで計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とする連続鋳造鋳型内の溶鋼流量制御方法。
［２］前記制御ステップでは、前記湯面レベル検出ステップで検出した湯面レベルが目標湯面レベルと略一致するように前記浸漬ノズルからの溶鋼流量を制御することを特徴とする［１］に記載の連続鋳造鋳型内の溶鋼流量制御方法。
［３］前記制御ステップでは、一定時間経過ごとに、前記湯面レベル検出ステップで検出した湯面レベルを、５ｍｍより大きく１５ｍｍ以下の範囲で定められた所定のレベルだけ上昇又は下降させるように前記浸漬ノズルからの溶鋼流量を制御することを特徴とする［１］又は［２］に記載の連続鋳造鋳型内の溶鋼流量制御方法。
［４］連続鋳造鋳型内の溶鋼流量を制御する溶鋼流量制御方法であって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を取得する取得ステップと、
前記取得ステップで取得した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算ステップと、
前記計算ステップで計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出ステップと、
前記湯面レベル検出ステップで検出した湯面レベルに基づいて、渦流式湯面計を較正する較正ステップと、
前記渦流式湯面計で検出した較正後の湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御ステップとを有し、
前記湯面レベル検出ステップでは、前記計算ステップで計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とする連続鋳造鋳型内の溶鋼流量制御方法。
［５］連続鋳造鋳型内の溶鋼流量を制御する溶鋼流量制御装置であって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を入力する入力手段と、
前記入力手段で入力した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算手段と、
前記計算手段で計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出手段と、
前記湯面レベル検出手段で検出した湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御手段とを備え、
前記湯面レベル検出手段は、前記計算手段で計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とする連続鋳造鋳型内の溶鋼流量制御装置。
［６］連続鋳造鋳型内の溶鋼流量を制御する溶鋼流量制御装置であって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を入力する入力手段と、
前記入力手段で入力した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算手段と、
前記計算手段で計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出手段と、
前記湯面レベル検出手段で検出した湯面レベルに基づいて、渦流式湯面計を較正する較正手段と、
前記渦流式湯面計で検出した較正後の湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御手段とを備え、
前記湯面レベル検出手段は、前記計算手段で計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とする連続鋳造鋳型内の溶鋼流量制御装置。
［７］連続鋳造鋳型内の溶鋼流量を制御するためのプログラムであって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を入力する入力処理と、
前記入力した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算処理と、
前記計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出処理と、
前記検出した湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御処理とをコンピュータに実行させ、
前記湯面レベル検出処理では、前記計算処理で計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とするプログラム。
［８］連続鋳造鋳型内の溶鋼流量を制御するためのプログラムであって、
前記連続鋳造鋳型の鋳造方向に配置、埋設された複数の温度検出手段の計測値を入力する入力処理と、
前記入力した前記温度検出手段の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向の成分値を計算する計算処理と、
前記計算した稼動面における熱流束の鋳造方向の成分値に基づいて、湯面レベルを検出する湯面レベル検出処理と、
前記検出した湯面レベルに基づいて、渦流式湯面計を較正する較正処理と、
前記渦流式湯面計で検出した較正後の湯面レベルに基づいて、浸漬ノズルからの溶鋼流量を制御する制御処理とをコンピュータに実行させ、
前記湯面レベル検出処理では、前記計算処理で計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向の成分値が最大となる位置を湯面レベルと判定することを特徴とするプログラム。 In order to solve the above problems, the present invention is as follows.
[1] A molten steel flow rate control method for controlling a molten steel flow rate in a continuous casting mold,
An acquisition step of acquiring measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation step for solving the inverse heat transfer problem using the measurement value of the temperature detection means acquired in the acquisition step and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the working surface calculated in the calculation step, a hot water surface level detecting step for detecting the hot water surface level,
Based on the molten metal surface level detected by the water level detecting step, it has a control step of controlling the molten steel flow from the immersion nozzle,
In the molten metal surface level detecting step, a position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculating step is determined as the molten metal surface level. A method for controlling the flow rate of molten steel in a continuous casting mold.
[ 2 ] In the control step, the molten steel flow rate from the immersion nozzle is controlled so that the molten metal surface level detected in the molten metal surface level detecting step substantially matches the target molten metal surface level . The molten steel flow rate control method in the continuous casting mold of description.
[ 3 ] In the control step, the hot water surface level detected in the hot water surface level detection step is increased or decreased by a predetermined level determined in a range of more than 5 mm and not more than 15 mm at every predetermined time. The method for controlling the flow rate of molten steel in a continuous casting mold according to [1] or [2] , wherein the flow rate of molten steel from an immersion nozzle is controlled.
[ 4 ] A molten steel flow rate control method for controlling a molten steel flow rate in a continuous casting mold,
An acquisition step of acquiring measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation step for solving the inverse heat transfer problem using the measurement value of the temperature detection means acquired in the acquisition step and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the working surface calculated in the calculation step, a hot water surface level detecting step for detecting the hot water surface level,
A calibration step for calibrating the eddy current level meter based on the level level detected in the level level detection step;
Based on the melt surface level after calibration detected by the vortex molten metal surface thermometer, it has a control step of controlling the molten steel flow from the immersion nozzle,
In the molten metal surface level detecting step, a position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculating step is determined as the molten metal surface level. A method for controlling the flow rate of molten steel in a continuous casting mold.
[ 5 ] A molten steel flow rate control device for controlling the molten steel flow rate in the continuous casting mold,
Input means for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation means for solving the inverse heat transfer problem using the measured value of the temperature detection means input by the input means, and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the operating surface calculated by the calculating means, a hot water surface level detecting means for detecting the hot water surface level,
Control means for controlling the flow rate of molten steel from the immersion nozzle based on the molten metal level detected by the molten metal level detecting means ;
The molten metal surface level detecting means determines that the position at which the component value in the normal direction of the molten metal surface opposite to the casting direction of the heat flux on the operating surface calculated by the calculating device is the maximum is the molten metal surface level. A control device for the flow rate of molten steel in a continuous casting mold.
[ 6 ] A molten steel flow rate control device for controlling a molten steel flow rate in a continuous casting mold,
Input means for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation means for solving the inverse heat transfer problem using the measured value of the temperature detection means input by the input means, and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the operating surface calculated by the calculating means, a hot water surface level detecting means for detecting the hot water surface level,
Calibration means for calibrating the eddy current type water level meter based on the level level detected by the level level detecting means,
Control means for controlling the flow rate of molten steel from the immersion nozzle based on the level of hot water after calibration detected by the vortex type hot water level meter ,
The molten metal surface level detecting means determines that the position at which the component value in the normal direction of the molten metal surface opposite to the casting direction of the heat flux on the operating surface calculated by the calculating device is the maximum is the molten metal surface level. A control device for the flow rate of molten steel in a continuous casting mold.
[ 7 ] A program for controlling the flow rate of molten steel in a continuous casting mold,
An input process for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation process for solving a heat transfer inverse problem using the input measurement value of the temperature detection means and calculating a component value in the casting direction of the heat flux on the working surface;
Based on the component value in the casting direction of the heat flux on the calculated operating surface, a hot water surface level detection process for detecting the hot water surface level ,
Based on the detected hot water level, the computer executes a control process for controlling the molten steel flow rate from the immersion nozzle ,
In the molten metal surface level detection process, the position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculation process is determined as the molten metal surface level. A featured program.
[ 8 ] A program for controlling the flow rate of molten steel in a continuous casting mold,
An input process for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation process for solving a heat transfer inverse problem using the input measurement value of the temperature detection means and calculating a component value in the casting direction of the heat flux on the working surface;
Based on the component value in the casting direction of the heat flux on the calculated operating surface, a hot water surface level detection process for detecting the hot water surface level ,
A calibration process for calibrating the eddy current level meter based on the detected level level;
Based on the calibrated molten metal level detected by the vortex flow meter, the computer executes a control process for controlling the molten steel flow rate from the immersion nozzle ,
In the molten metal surface level detection process, the position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculation process is determined as the molten metal surface level. A featured program.

本発明によれば、湯面位置における熱移動の影響を捉えて湯面レベルを検出することにより湯面レベルの検出精度を高め、溶鋼流量制御を高精度化して、安定操業を実現することができる。 According to the present invention, it is possible to increase the accuracy of detection of the molten metal level by detecting the level of the molten metal level by detecting the influence of the heat transfer at the molten metal surface position, and to realize a stable operation by increasing the accuracy of the molten steel flow rate control. it can.

第１の実施形態における連続鋳造鋳型の概要を模式的に示す図である。It is a figure which shows typically the outline | summary of the continuous casting mold in 1st Embodiment. 第１の実施形態における熱電対の配置を示す図である。It is a figure which shows arrangement | positioning of the thermocouple in 1st Embodiment. 第１の実施形態に係る連続鋳造鋳型内の溶鋼流量制御装置の機能構成を示す図である。It is a figure which shows the function structure of the molten steel flow control apparatus in the continuous casting mold which concerns on 1st Embodiment. 伝熱逆問題の座標系を示す図である。It is a figure which shows the coordinate system of a heat transfer inverse problem. 湯面レベルの検出の概要を説明するための図である。It is a figure for demonstrating the outline | summary of the detection of a hot-water surface level. 湯面レベルを実測するための装置構成例を示す図である。It is a figure which shows the example of an apparatus structure for measuring a hot_water | molten_metal surface level. 本発明の手法で検出した湯面レベルと、既存の手法で検出した湯面レベルと、実測の湯面レベルとを示す特性図である。It is a characteristic view which shows the hot-water surface level detected with the method of this invention, the hot-water surface level detected with the existing method, and the measured hot-water surface level. 第１の実施形態において制御部が実行する制御処理を示すフローチャートである。It is a flowchart which shows the control processing which a control part performs in 1st Embodiment. 第２の実施形態に係る連続鋳造鋳型内の溶鋼流量制御装置の機能構成を示す図である。It is a figure which shows the function structure of the molten steel flow control apparatus in the continuous casting mold which concerns on 2nd Embodiment.

以下、添付図面を参照して、本発明の好適な実施形態について説明する。
［第１の実施形態］
図１に、連続鋳造鋳型（以下、単に鋳型と呼ぶ）１の概要を模式的に示す。鋳型１は、互いに対向する一対の鋳型短辺２ａ、２ｂと、互いに対向する一対の鋳型長辺３ａ、３ｂとにより構成される。鋳型１の内面を稼動面、外面を水冷面と呼ぶ。即ち、鋳型１の各面のうち、溶湯に接する面が稼動面である（ただし、潤滑パウダーを用いる場合は該潤滑パウダーを通して溶湯に接する）。
鋳型１の中央には浸漬ノズル４が配置されており、浸漬ノズル４の左右の吐出孔４ａ、４ｂから左右の鋳型短辺２ａ、２ｂへ向かって溶鋼が吐出される。符号５は、湯面を示す。なお、図１は左右一対の吐出孔４ａ、４ｂを有する例を示すが、吐出孔は左右複数対あってもよい。 Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 schematically shows an outline of a continuous casting mold (hereinafter simply referred to as a mold) 1. The mold 1 includes a pair of mold short sides 2a and 2b facing each other and a pair of mold long sides 3a and 3b facing each other. The inner surface of the mold 1 is called the working surface, and the outer surface is called the water-cooled surface. That is, of the surfaces of the mold 1, the surface that contacts the molten metal is the working surface (however, when lubricating powder is used, it contacts the molten metal through the lubricating powder).
An immersion nozzle 4 is disposed at the center of the mold 1, and molten steel is discharged from the left and right discharge holes 4 a, 4 b of the immersion nozzle 4 toward the left and right mold short sides 2 a, 2 b. Reference numeral 5 indicates a hot water surface. Although FIG. 1 shows an example having a pair of left and right discharge holes 4a and 4b, a plurality of right and left discharge holes may be provided.

一対の鋳型長辺３ａ、３ｂには、鋳造方向に複数の熱電対６が配置、埋設される。図１２に示すように、本実施形態では、鋳型長辺３ａ、３ｂに、それぞれ２列で熱電対６を配置、埋設する。
図１に示す熱電対６の配置は一例に過ぎず、例えば一対の鋳型短辺２ａ、２ｂに、鋳造方向に複数の熱電対６を配置、埋設するようにしてもよい。ただし、鋳型１内に流入する溶鋼流量に起因する湯面変動を捉える意味からいうと、偏流の影響をさけるために、浸漬ノズル４の吐出流が衝突する鋳型短辺２ａ、２ｂから離れた位置での湯面レベルを捉えるのが好ましい。そこで、本実施形態では、図２に示すように、浸漬ノズル４の中心から左右鋳型短辺２ａ、２ｂまでの鋳型長辺幅方向距離をそれぞれＷ／２とした場合に、鋳型長辺３ａ、３ｂにおいて、浸漬ノズル４の中心から３Ｗ／８以内に熱電対６を配置、埋設するようにしている。 A plurality of thermocouples 6 are arranged and embedded in the pair of mold long sides 3a and 3b in the casting direction. As shown in FIG. 12, in this embodiment, the thermocouples 6 are arranged and embedded in two long rows on the long mold sides 3a and 3b.
The arrangement of the thermocouple 6 shown in FIG. 1 is merely an example. For example, a plurality of thermocouples 6 may be arranged and embedded in the casting direction on the pair of mold short sides 2a and 2b. However, in terms of capturing the fluctuation of the molten metal surface caused by the flow rate of the molten steel flowing into the mold 1, in order to avoid the influence of uneven flow, the position away from the mold short sides 2a and 2b where the discharge flow of the immersion nozzle 4 collides. It is preferable to capture the level of the hot water at. Therefore, in the present embodiment, as shown in FIG. 2, when the mold long side width direction distance from the center of the immersion nozzle 4 to the left and right mold short sides 2a and 2b is W / 2, the mold long side 3a, In 3b, the thermocouple 6 is arranged and embedded within 3 W / 8 from the center of the immersion nozzle 4.

図３に、第１の実施形態に係る連続鋳造鋳型内の溶鋼流量制御装置１００の機能構成を示す。
１０１は入力部であり、鋳型１の鋳造方向に配置、埋設された複数の熱電対６の計測値を入力する。本実施形態では、各列の熱電対６の計測値が入力される。
１０２は計算部であり、詳細は後述するが、入力部１０１で入力した熱電対６の計測値を用いて伝熱逆問題を解き、稼動面における熱流束の鋳造方向のベクトル成分値、換言すれば稼動面における熱流束の湯面に垂直な方向のベクトル成分値を計算する。
１０３は湯面レベル検出部であり、計算部１０２で計算した稼動面における熱流束の鋳造方向と逆向きとなる湯面の法線方向のベクトル成分値が最大となる位置を湯面レベルと判定する。
本実施形態のように複数列で熱電対６を配置する場合、計算部１０２及び湯面レベル検出部１０３において、列ごとに熱電対６の計測値を用いて湯面レベルを推定し、これら湯面レベルの平均値を現在の湯面レベルとして取り扱うようにすればよい。
１０４は制御部であり、詳細は後述するが、湯面レベル検出部１０３で検出した湯面レベルに基づいて、浸漬ノズル４からの溶鋼流量を制御する。
入力部１０１、計算部１０２、湯面レベル検出部１０３、及び制御部１０４は、例えば一定周期で、熱電対６の計測値の入力、ベクトル成分値の計算、湯面レベルの検出、及び溶鋼流量の制御を実行する。 FIG. 3 shows a functional configuration of the molten steel flow rate control device 100 in the continuous casting mold according to the first embodiment.
Reference numeral 101 denotes an input unit that inputs measurement values of a plurality of thermocouples 6 arranged and embedded in the casting direction of the mold 1. In this embodiment, the measured value of the thermocouple 6 in each column is input.
Reference numeral 102 denotes a calculation unit, which will be described in detail later, but solves the inverse heat transfer problem using the measured value of the thermocouple 6 input by the input unit 101, in other words, the vector component value in the casting direction of the heat flux on the operating surface, in other words For example, the vector component value in the direction perpendicular to the molten metal surface of the heat flux on the operating surface is calculated.
103 is a molten metal surface level detection unit, and the position where the vector component value in the normal direction of the molten metal surface opposite to the casting direction of the heat flux on the working surface calculated by the calculation unit 102 is determined as the molten metal surface level. To do.
When the thermocouples 6 are arranged in a plurality of rows as in the present embodiment, the calculation unit 102 and the hot water surface level detection unit 103 estimate the hot water surface level using the measured value of the thermocouple 6 for each row, and these hot water levels. The average value of the surface level may be handled as the current hot water surface level.
Reference numeral 104 denotes a control unit that controls the flow rate of molten steel from the immersion nozzle 4 based on the molten metal level detected by the molten metal level detecting unit 103, as will be described in detail later.
The input unit 101, the calculation unit 102, the molten metal level detection unit 103, and the control unit 104 are, for example, at regular intervals, input of measured values of the thermocouple 6, calculation of vector component values, detection of molten metal level, and molten steel flow rate. Execute the control.

（湯面レベルの検出について）
連続鋳造操業においては、鋳型１内にパウダーを添加して、溶鋼の保温及び酸化防止、溶鋼中の介在物の吸収、凝固シェルの潤滑性の確保、抜熱の調整をする。これにより、鋳型内メニスカスでの凝固シェルを均一に生成して表面割れを防止し、鋳型と凝固シェルの焼き付きを防止する。
このように鋳型１内の湯面上にはパウダーが供給されることから、本発明では「パウダーによる抜熱の影響で湯面に垂直で上向きの熱流束値は、鋳型の他の部位と比べて最も大きくなる。」という推論に基づき、湯面レベルを検出する。 (About detection of hot water level)
In the continuous casting operation, powder is added into the mold 1 to keep the molten steel warm and prevent oxidation, absorb inclusions in the molten steel, ensure the lubricity of the solidified shell, and adjust the heat removal. As a result, a solidified shell is uniformly formed at the meniscus in the mold to prevent surface cracks, and seizure between the mold and the solidified shell is prevented.
Since powder is supplied onto the molten metal surface in the mold 1 in this way, in the present invention, “the heat flux value perpendicular to the molten metal surface and upward due to the effect of heat removal by the powder is compared with other parts of the mold. The hot water level is detected based on the inference that “It is the largest.”

以下、鋳型１に埋設された複数の熱電対６の計測データに基づいて、稼働面の熱流束ベクトルを推定する伝熱逆問題を説明する。
温度推定のための内外挿温度関数ｕ^*を、鋳型１に埋設された複数の熱電対６の時系列データセットに基づいて、鋳型１の鋳造方向−抜熱方向の２次元断面温度分布の時間変化を予測する数式を作成する。同式に基づいて、稼働面における熱流束ベクトル（大きさと向き）を求め、湯面レベル判定のための基本物理量とする。 Hereinafter, the inverse heat transfer problem for estimating the heat flux vector of the working surface based on the measurement data of the plurality of thermocouples 6 embedded in the mold 1 will be described.
Based on the time series data set of a plurality of thermocouples 6 embedded in the mold 1, the time of the two-dimensional cross-sectional temperature distribution in the casting direction and the heat removal direction of the mold 1 is used as the extrapolated temperature function u ^* for temperature estimation. Create mathematical formulas to predict changes. Based on this formula, the heat flux vector (size and direction) on the working surface is obtained and used as a basic physical quantity for determining the molten metal surface level.

図４に、伝熱逆問題の座標系を示す。空間ｘ軸は稼働面をｘ＝０とする抜熱方向、空間ｙ軸は鋳型１の上端をｙ＝０とする鋳造方向であり、これらに時間軸ｔを加えた時空間３次元座標を考える。
図４のプロットは、あるｙにおける空間ｘ−時間ｔの２次元断面図上の計算に使用する情報量の定義点を示す。ｘ軸の熱電対位置の情報量は熱電対６の計測データを使う。一方、水冷面の位置には熱電対が無いので、水冷熱伝達係数と水温を既知として決まる熱流束値を情報量に使い、上述した熱電対位置と併せ、測温データ採取点の領域と定義する。この領域をｙ軸方向にある熱電対位置に拡張し、空間ｘ−空間ｙ−時間ｔの３次元測温データ採取点の領域とする。
上述した３次元測温データ採取点の領域の情報量に基づいて作成した内外挿温度関数ｕ^*(ｘ，ｙ，ｔ)を使って、稼働面における熱流束ベクトルを推定する。 FIG. 4 shows a coordinate system for the inverse heat transfer problem. The space x-axis is the heat removal direction where the working surface is x = 0, and the space y-axis is the casting direction where the upper end of the mold 1 is y = 0. .
The plot of FIG. 4 shows the definition points of the information amount used for the calculation on the two-dimensional sectional view of the space x-time t at a certain y. The measurement data of the thermocouple 6 is used as the information amount of the thermocouple position on the x axis. On the other hand, since there is no thermocouple at the position of the water-cooled surface, the heat-cooled heat transfer coefficient and the heat flux value determined as the water temperature are used as the information amount, and together with the above-mentioned thermocouple position, it is defined as the temperature measurement data collection point area To do. This region is expanded to the thermocouple position in the y-axis direction, and is set as a region of the three-dimensional temperature measurement data collection point in space x-space y-time t.
The heat flux vector on the working surface is estimated using the interpolated temperature function u ^* (x, y, t) created based on the information amount of the region of the three-dimensional temperature measurement data collection point described above.

以下に、内外挿温度関数ｕ^*(ｘ，ｙ，ｔ)を構成するための数学手続きを述べる。
式（１）の非定常熱伝導方程式を考える。ここで、ａは鋳型１の熱拡散係数の平方根の物理量である。位置座標ｘ，ｙは[０，１]で規格化した。 The mathematical procedure for constructing the extrapolated temperature function u ^* (x, y, t) is described below.
Consider the unsteady heat conduction equation of equation (1). Here, a is a physical quantity of the square root of the thermal diffusion coefficient of the mold 1. The position coordinates x and y are normalized by [0, 1].

冷却面の境界条件を式（２）で表す。ここで、ｇ(ｔ)＝ｕ_wγとし、水温ｕ_wと熱伝達係数γの積として定義した。βは鋳型１の熱伝導率である。 The boundary condition of the cooling surface is expressed by equation (2). Here, g (t) = u _w γ, which is defined as the product of the water temperature u _w and the heat transfer coefficient γ. β is the thermal conductivity of the mold 1.

鋳型１の熱電対温度情報を式（３）で記述する。ｘ^*，ｙ^*は熱電対位置を表し、[０，１]で規格化している。 The thermocouple temperature information of the mold 1 is described by equation (3). x ^* and y ^* represent thermocouple positions and are normalized by [0, 1].

内外挿温度関数ｕ^*(ｘ，ｙ，ｔ)は後述する基底関数φを使い、式（４）で記述する。 The interpolated temperature function u ^* (x, y, t) is described by equation (4) using a basis function φ described later.

係数λ_jは、行列方程式（５）を解いて決定する。ここで、Ａは（ｍ＋ｌ）×（ｍ＋ｌ）行列、ｂは（ｍ＋ｌ）ベクトルである。ｘ_k，ｘ_s，ｔ_k，ｔ_sは上述の測温データ採取点の領域にある情報量の定義点である。一方、ｘ_j，ｔ_jは中心点と呼ばれる時空間座標上での基準点の座標であり、通常は、情報量の定義点と同一点を採用しておけばよい。 The coefficient λ _j is determined by solving the matrix equation (5). Here, A is an (m + 1) × (m + 1) matrix, and b is an (m + 1) vector. x _k , x _s , t _k , and t _s are definition points of the information amount in the region of the temperature measurement data collection point. On the other hand, x _j and t _j are the coordinates of the reference point on the spatio-temporal coordinate called the center point, and usually the same point as the definition point of the information amount may be adopted.

次に、基底関数φを、式（１）式を満足する基本解の形式を使い、式（６）、（７）のように定義する。 Next, the basis function φ is defined as in equations (6) and (7) using a basic solution format that satisfies equation (1).

ここで、Ｔは基本解の拡散プロフィールを調整するパラメータであり、Ｈ(ｔ)はヘビサイド関数である。稼働面における熱流束のｙ方向成分ｑ_yは、式（８）で計算することができる。ｋは鋳型材料の熱伝導率である。 Here, T is a parameter for adjusting the diffusion profile of the basic solution, and H (t) is a snake side function. The y-direction component q _y of the heat flux on the operating surface can be calculated by equation (8). k is the thermal conductivity of the mold material.

実機において、本発明の手法で湯面レベルを検出し、既存の手法で検出した湯面レベル及び実測の湯面レベルと比較した。この比較においては、鋳型短辺の鋳造方向に複数の熱電対６を配置、埋設している。
本発明の手法では、図５（ｃ）、（ｄ）に示すように、稼動面における熱流束の鋳造方向のベクトル成分値を計算し、それが最大となる位置を湯面レベルと判定する。図５（ｃ）には、鋳型１内の温度分布（ドットが濃いほど高温であることを示す）と、稼動面における熱流束とを示す。図５（ｄ）には、稼動面における熱流束の鋳造方向のベクトル成分値を示す。 In the actual machine, the molten metal level was detected by the method of the present invention, and compared with the molten metal level detected by the existing method and the measured molten metal level. In this comparison, a plurality of thermocouples 6 are arranged and embedded in the casting direction of the mold short side.
In the method of the present invention, as shown in FIGS. 5C and 5D, the vector component value in the casting direction of the heat flux on the working surface is calculated, and the position where it becomes the maximum is determined as the molten metal level. FIG. 5C shows the temperature distribution in the mold 1 (the darker the dot, the higher the temperature) and the heat flux on the operating surface. In FIG.5 (d), the vector component value of the casting direction of the heat flux in an operation surface is shown.

一方、既存の手法では、図５（ｂ）に示すように、鋳型１内の温度分布を計算し、経験則に基づいて、最高温度×０．６５となる位置を湯面レベルと判定する。 On the other hand, in the existing method, as shown in FIG. 5B, the temperature distribution in the mold 1 is calculated, and the position where the maximum temperature × 0.65 is determined as the hot water level based on the empirical rule.

また、図６に示すように、湯面にフロート５０１を浮かべ、フロート５０１にロッド５０２を設けている。また、オッシレーション測定治具５０３を設定している。そして、ロッド５０２の先端、オッシレーション測定金物先端の動きをビデオカメラ５０４で撮影し、画像処理により垂直方向の変位をデジタル化し記録することにより、湯面レベルを実測した。 Further, as shown in FIG. 6, a float 501 is floated on the hot water surface, and a rod 502 is provided on the float 501. In addition, an oscillation measurement jig 503 is set. Then, the movement of the tip of the rod 502 and the tip of the oscillation measurement hardware were photographed by the video camera 504, and the vertical surface level was measured by digitizing and recording the displacement in the vertical direction by image processing.

図７に、本発明の手法で検出した湯面レベルと、既存の手法で検出した湯面レベルと、実測の湯面レベルとを示す。横軸は時間を、縦軸は湯面レベルを示す。
既存の手法では、実測の湯面レベルが高くなると検出精度が極端に低下し、実測値に追従できなくなっている。
それに対して、本発明の手法では、広範囲に亘り実測値を追従できているのがわかる。湯面レベルの実測精度が５−１０ｍｍ程度のバラツキがあることを勘案すると、本発明の手法により検出した湯面レベルは実測の湯面レベルと良い対応関係にあるといえる。 FIG. 7 shows the molten metal level detected by the method of the present invention, the molten metal level detected by the existing method, and the measured molten metal level. The horizontal axis represents time, and the vertical axis represents the hot water level.
In the existing method, when the measured hot water level becomes high, the detection accuracy is extremely lowered, and the measured value cannot be tracked.
On the other hand, it can be seen that the measured values can be tracked over a wide range in the method of the present invention. Considering that there is a variation in the measured accuracy of the molten metal level of about 5-10 mm, it can be said that the molten metal level detected by the method of the present invention has a good correspondence with the measured molten metal level.

以上述べたように、パウダーによる抜熱という湯面位置における熱移動の影響を捉えて湯面レベルを検出するので、湯面レベルの検出精度を高めることができる。 As described above, since the hot water level is detected by detecting the influence of heat transfer at the hot water surface position of heat removal by powder, the detection accuracy of the hot water level can be improved.

（制御部１０４の処理について）
図８に、制御部１０４が実行する制御処理を示す。図８に示す制御処理は、湯面レベル検出部１０３で検出した湯面レベルが目標湯面レベルと略一致するように浸漬ノズル４からの溶鋼流量を制御する。
ステップＳ８０１で、制御部１０４は、湯面レベル検出部１０３から湯面レベルを取得する。
ステップＳ８０２で、制御部１０４は、ステップＳ８０１で取得した湯面レベルが目標湯面レベルを超えているか否か、本例では（湯面レベル−目標湯面レベル）＞２ｍｍであるか否かを判定する。湯面レベルが目標湯面レベルを超えていれば、ステップＳ８０３に進み、超えていなければ、ステップＳ８０４に進む。
ステップＳ８０３で、制御部１０４は、浸漬ノズル４の上流に設置したスライディングノズル（図示せず）の開度を制御して溶鋼流量を減らし、湯面レベルが目標湯面レベルに近づくようにする。なお、スライディングノズルの代わりに、タンディッシュ（図示せず）内に設けたストッパーを上下させて溶鋼流量を制御してもよい。 (About processing of the control unit 104)
FIG. 8 shows control processing executed by the control unit 104. The control process shown in FIG. 8 controls the molten steel flow rate from the immersion nozzle 4 so that the molten metal level detected by the molten metal level detecting unit 103 substantially matches the target molten metal level.
In step S <b> 801, the control unit 104 acquires the hot water level from the hot water level detection unit 103.
In step S802, the control unit 104 determines whether or not the hot water surface level acquired in step S801 exceeds the target hot water surface level, in this example, (hot water surface level−target hot water surface level)> 2 mm. judge. If the hot water level exceeds the target hot water level, the process proceeds to step S803, and if not, the process proceeds to step S804.
In step S803, the control unit 104 controls the opening of a sliding nozzle (not shown) installed upstream of the immersion nozzle 4 to reduce the flow rate of the molten steel so that the molten metal level approaches the target molten metal level. Instead of the sliding nozzle, the flow rate of the molten steel may be controlled by moving up and down a stopper provided in a tundish (not shown).

ステップＳ８０４で、制御部１０４は、ステップＳ８０１で取得した湯面レベルが目標湯面レベルを下回っているか否か、本例では（目標湯面レベル−湯面レベル）＞２ｍｍであるか否かを判定する。湯面レベルが目標湯面レベルを下回っていれば、ステップＳ８０５に進み、下回っていなければ、本処理を抜ける。
ステップＳ８０５で、制御部１０４は、浸漬ノズル４の上流に設置したスライディングノズルの開度を制御して溶鋼流量を増やし、湯面レベルが目標湯面レベルに近づくようにする。ステップ８０４と同様に、スライディングノズルの代わりに、ストッパーを上下させて溶鋼流量を制御してもよい。 In step S804, the control unit 104 determines whether or not the hot water surface level acquired in step S801 is lower than the target hot water surface level, in this example (target hot water surface level−hot water surface level)> 2 mm. judge. If the hot water level is lower than the target hot water level, the process proceeds to step S805, and if not lower, the process is exited.
In step S805, the control unit 104 controls the opening degree of the sliding nozzle installed upstream of the immersion nozzle 4 to increase the flow rate of the molten steel so that the molten steel surface level approaches the target molten metal surface level. Similar to step 804, the molten steel flow rate may be controlled by moving the stopper up and down instead of the sliding nozzle.

ここで、本実施形態では閾値を２ｍｍとしたが、これに限定されるものではない。閾値を２ｍｍとしたのは、後述するように湯面レベル検出部１０３での湯面レベルの検出誤差が２ｍｍ程度ありえるので、±２ｍｍの範囲であれば、湯面レベル検出部１０３で検出した湯面レベルが目標湯面レベルと略一致しているとみなすことにしたものである。 Here, although the threshold value is 2 mm in the present embodiment, the present invention is not limited to this. The reason why the threshold value is set to 2 mm is that there is about 2 mm of detection error of the hot water level in the hot water level detecting unit 103 as will be described later. Therefore, the hot water level detected by the hot water level detecting unit 103 is within a range of ± 2 mm. It is assumed that the surface level substantially matches the target hot water surface level.

また、制御部１０４は、図８に示した制御処理とは別に、浸漬ノズルパウダーラインの局部的な溶損を防止するために、鋳造中の一定時間経過ごとに浸漬ノズル４の浸漬深さを変更する。具体的には、例えば６０分経過ごとに、そのときに湯面レベル検出部１０３で検出した湯面レベルを、５ｍｍより大きく１５ｍｍ以下の範囲で定められた所定のレベルだけ上昇させるように浸漬ノズル４からの溶鋼流量を制御する。
ここで、湯面レベルを５ｍｍより大きく１５ｍｍ以下の範囲で定められた所定のレベルだけ上昇させる理由を説明する。一般的にパウダーの厚みは５ｍｍ程度あるので、それを超えるように浸漬深さを変更しなければ、浸漬ノズル４の局所的な溶損を効果的に防ぐことができないからである。また、１５ｍｍを超える湯面変動は、鋳片品質に影響を与えるおそれがあるからである。
なお、湯面レベルを上昇させると説明したが、下降させるようにしてもよい。ただし、上昇と下降を繰り返すのでは、浸漬ノズル４の局所的な溶損を効果的に避けることができないので、上昇又は下降の一方向に湯面レベルを変更するものとする。必要であれば、上昇又は下降の一方向に数段階で湯面レベルを変更した後に、他方向に数段階で湯面レベルを変更するように切り替えてもよい。 In addition to the control processing shown in FIG. 8, the control unit 104 sets the immersion depth of the immersion nozzle 4 every certain time during casting in order to prevent local melting of the immersion nozzle powder line. change. Specifically, for example, every 60 minutes, the immersion nozzle level is increased by a predetermined level determined within a range of more than 5 mm and less than or equal to 15 mm by the molten metal level detection unit 103 at that time. 4 to control the flow rate of molten steel.
Here, the reason why the hot water level is raised by a predetermined level that is set in a range of 5 mm to 15 mm will be described. This is because, in general, the thickness of the powder is about 5 mm, and unless the immersion depth is changed so as to exceed the thickness, local melting damage of the immersion nozzle 4 cannot be effectively prevented. Moreover, it is because the hot-water surface fluctuation | variation exceeding 15 mm may affect slab quality.
In addition, although demonstrated that the hot water surface level was raised, you may make it fall. However, repeating the ascent and descent cannot effectively avoid local melting of the immersion nozzle 4, and therefore the hot water level is changed in one direction of ascending or descending. If necessary, after changing the hot water level in several steps in one direction of rising or lowering, the hot water level may be changed in several steps in the other direction.

表１に、従来技術１と、従来技術２と、本法（実施形態の手法）とにおいて、湯面レベル検出精度（ｍｍ）と、浸漬ノズルパウダーライン溶損量（ｍｍ／２ｈ）とを比較した結果を示す。従来技術１は、従来の渦流式湯面計を用いた例である。また、従来技術２は、図５（ｂ）に示したように、鋳型１内の温度分布を計算し、最高温度×０．６５となる位置を湯面レベルと判定した例である。鋳造条件は、鋳造厚：２５０ｍｍ、鋳造幅：１２５０ｍｍ、鋳造速度：１．４ｍｐｍ、モールド上端〜湯面位置：１００ｍｍ、鋼種：低炭ＡＬ−Ｋ鋼である。 Table 1 compares hot water level detection accuracy (mm) and immersion nozzle powder line erosion amount (mm / 2h) in Conventional Technology 1, Conventional Technology 2, and this method (the method of the embodiment). The results are shown. Prior art 1 is an example using a conventional eddy current level meter. Prior art 2 is an example in which, as shown in FIG. 5B, the temperature distribution in the mold 1 is calculated, and the position where the maximum temperature × 0.65 is determined as the hot water level. The casting conditions are casting thickness: 250 mm, casting width: 1250 mm, casting speed: 1.4 mpm, mold upper end to molten metal surface position: 100 mm, steel type: low-char AL-K steel.

表１に示すように、従来技術１では湯面レベル検出精度（ｍｍ）が±２０、従来技術２では湯面レベル検出精度が±１５ある。このように湯面レベル検出精度が±１５ｍｍを超えているため、浸漬ノズル４の浸漬深さを１５ｍｍ以下の範囲で変更しても、浸漬ノズルパウダーラインの局部的な溶損を効果的に防ぐことができない。そのため、浸漬ノズルパウダーライン溶損量（ｍｍ／２ｈ）はそれぞれ１５、１３と大きくなっている。
それに対して、本法では湯面レベル検出精度（ｍｍ）が±２と大幅に改善されており、浸漬ノズルパウダーライン溶損量（ｍｍ／２ｈ）も３となり、浸漬ノズルパウダーラインの局部的な溶損を効果的に防ぐことができる。
以上述べたように、湯面位置における熱移動の影響を捉えて湯面レベルを検出することにより湯面レベルの検出精度を高め、鋳型内の偏流の検知精度向上を図り、鋳片品質の安定化を実現することができる。 As shown in Table 1, in the prior art 1, the hot water level detection accuracy (mm) is ± 20, and in the conventional technology 2, the hot water level detection accuracy is ± 15. Thus, even if the immersion depth of the immersion nozzle 4 is changed within a range of 15 mm or less, the local melt damage of the immersion nozzle powder line is effectively prevented because the accuracy of detecting the molten metal level exceeds ± 15 mm. I can't. Therefore, the immersion nozzle powder line melting loss (mm / 2h) is as large as 15 and 13, respectively.
On the other hand, in this method, the level detection accuracy (mm) is greatly improved to ± 2, and the immersion nozzle powder line erosion amount (mm / 2h) is also 3, which is a local level of the immersion nozzle powder line. Melting damage can be effectively prevented.
As described above, the detection accuracy of the molten metal level is improved by detecting the level of the molten metal level by detecting the influence of heat transfer at the molten metal surface position, and the detection accuracy of the drift in the mold is improved, and the quality of the slab is stabilized. Can be realized.

［第２の実施形態］
第２の実施形態は、パウダーによる抜熱という湯面位置における熱移動の影響を捉えて湯面レベルを検出することは第１の実施形態と共通であるが、検出した湯面レベルに基づいて、渦流式湯面計を較正するようにした例である。 [Second Embodiment]
In the second embodiment, it is common to the first embodiment to detect the level of the molten metal surface by detecting the influence of heat transfer at the molten metal surface position of heat removal by powder, but based on the detected molten metal surface level. This is an example of calibrating the vortex flow meter.

図９に、連続鋳造鋳型内の溶鋼流量制御装置２００の機能構成を示す。溶鋼流量制御装置２００には、渦流式湯面計３００が接続する。
入力部２０１、計算部２０２、及び湯面レベル検出部２０３は、第１の実施形態の入力部１０１、計算部１０２、及び湯面レベル検出部１０３と同様であり、その説明を省略する。
２０４は較正部であり、湯面レベル検出部１０３で検出した湯面レベルに基づいて、渦流式湯面計３００を較正する。較正の仕方は限定されるものではないが、所定のタイミングで（例えば鋳造スタート時）、湯面レベル検出部１０３で検出した湯面レベルと、渦流式湯面計３００で検出した湯面レベルとの差を求める。そして、その差を補正値として記憶しておき、以降、渦流式湯面計３００で検出した湯面レベルを補正値を用いて補正する形態とすればよい。
２０５は制御部であり、渦流式湯面計３００で検出した較正後の湯面レベルに基づいて、浸漬ノズル４からの溶鋼流量を制御する。制御部２０５の処理については、渦流式湯面計３００で検出した較正後の湯面レベルを用いる点以外は第１の実施形態と同様であり、その説明を省略する。 FIG. 9 shows a functional configuration of the molten steel flow rate control device 200 in the continuous casting mold. The molten steel flow rate control device 200 is connected to the eddy current level meter 300.
The input unit 201, the calculation unit 202, and the hot water surface level detection unit 203 are the same as the input unit 101, the calculation unit 102, and the hot water surface level detection unit 103 of the first embodiment, and a description thereof will be omitted.
Reference numeral 204 denotes a calibration unit that calibrates the eddy current level meter 300 based on the level level detected by the level level detection unit 103. The method of calibration is not limited, but at a predetermined timing (for example, at the start of casting), the molten metal level detected by the molten metal level detecting unit 103 and the molten metal level detected by the eddy current type molten metal level meter 300 Find the difference. Then, the difference may be stored as a correction value, and thereafter, the hot water level detected by the vortex type hot water level meter 300 may be corrected using the correction value.
Reference numeral 205 denotes a control unit that controls the flow rate of molten steel from the immersion nozzle 4 on the basis of the calibrated hot water level detected by the vortex flow meter 300. About the process of the control part 205, it is the same as that of 1st Embodiment except the point which uses the hot water surface level after the calibration detected with the eddy current type hot water surface meter 300, The description is abbreviate | omitted.

以上、本発明を種々の実施形態と共に説明したが、本発明はこれらの実施形態にのみ限定されるものではなく、発明の範囲内で変更等が可能である。
本発明を適用した連続鋳造鋳型内の溶鋼流量制御装置は、例えばＣＰＵ、ＲＯＭ、ＲＡＭ等を備えたコンピュータ装置により実現することが可能である。
また、本発明は、連続鋳造鋳型内の溶鋼流量制御機能を実現するソフトウェア（プログラム）を、ネットワーク又は各種記憶媒体を介してシステム或いは装置に供給し、そのシステム或いは装置のコンピュータがプログラムを読み出して実行することによっても実現可能である。 As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the invention.
The molten steel flow rate control device in the continuous casting mold to which the present invention is applied can be realized by a computer device including a CPU, a ROM, a RAM, and the like, for example.
The present invention also provides software (program) for realizing a molten steel flow rate control function in a continuous casting mold to a system or apparatus via a network or various storage media, and the computer of the system or apparatus reads the program. It can also be realized by executing.

１：連続鋳造鋳型、２ａ、２ｂ：鋳型短辺、３ａ、３ｂ：鋳型長辺、４：浸漬ノズル、５：湯面、６：熱電対、１００：連続鋳造鋳型内の溶鋼流量制御装置、１０１：入力部、１０２：計算部、１０３：湯面レベル検出部、１０４：制御部、２００：連続鋳造鋳型内の湯面変動制御装置、２０１：入力部、２０２：計算部、２０３：湯面レベル検出部、２０４：較正部、２０５：制御部、３００：渦流式湯面計 1: Continuous casting mold, 2a, 2b: Mold short side, 3a, 3b: Mold long side, 4: Immersion nozzle, 5: Molten surface, 6: Thermocouple, 100: Molten steel flow control device in continuous casting mold, 101 : Input unit, 102: calculation unit, 103: hot water level detection unit, 104: control unit, 200: hot water level fluctuation control device in continuous casting mold, 201: input unit, 202: calculation unit, 203: hot water level Detection unit, 204: calibration unit, 205: control unit, 300: vortex flow meter

Claims

A molten steel flow rate control method for controlling a molten steel flow rate in a continuous casting mold,
An acquisition step of acquiring measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation step for solving the inverse heat transfer problem using the measurement value of the temperature detection means acquired in the acquisition step and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the working surface calculated in the calculation step, a hot water surface level detecting step for detecting the hot water surface level,
Based on the molten metal surface level detected by the water level detecting step, it has a control step of controlling the molten steel flow from the immersion nozzle,
In the molten metal surface level detecting step, a position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculating step is determined as the molten metal surface level. A method for controlling the flow rate of molten steel in a continuous casting mold.

2. The continuous control according to claim 1 , wherein in the control step, the molten steel flow rate from the immersion nozzle is controlled so that the molten metal level detected in the molten metal level detection step substantially coincides with a target molten metal level. A method for controlling the flow rate of molten steel in a casting mold.

In the control step, from the immersion nozzle, the hot water level detected in the hot water level detection step is increased or decreased by a predetermined level determined in a range of greater than 5 mm and 15 mm or less at every predetermined time. molten steel flow control method of continuous casting in the mold according to claim 1 or 2, characterized in that for controlling the molten steel flow.

A molten steel flow rate control method for controlling a molten steel flow rate in a continuous casting mold,
An acquisition step of acquiring measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation step for solving the inverse heat transfer problem using the measurement value of the temperature detection means acquired in the acquisition step and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the working surface calculated in the calculation step, a hot water surface level detecting step for detecting the hot water surface level,
A calibration step for calibrating the eddy current level meter based on the level level detected in the level level detection step;
Based on the melt surface level after calibration detected by the vortex molten metal surface thermometer, it has a control step of controlling the molten steel flow from the immersion nozzle,
In the molten metal surface level detecting step, a position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculating step is determined as the molten metal surface level. A method for controlling the flow rate of molten steel in a continuous casting mold.

A molten steel flow rate control device for controlling the molten steel flow rate in a continuous casting mold,
Input means for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation means for solving the inverse heat transfer problem using the measured value of the temperature detection means input by the input means, and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the operating surface calculated by the calculating means, a hot water surface level detecting means for detecting the hot water surface level,
Control means for controlling the flow rate of molten steel from the immersion nozzle based on the molten metal level detected by the molten metal level detecting means ;
The molten metal surface level detecting means determines that the position at which the component value in the normal direction of the molten metal surface opposite to the casting direction of the heat flux on the operating surface calculated by the calculating device is the maximum is the molten metal surface level. A control device for the flow rate of molten steel in a continuous casting mold.

A molten steel flow rate control device for controlling the molten steel flow rate in a continuous casting mold,
Input means for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation means for solving the inverse heat transfer problem using the measured value of the temperature detection means input by the input means, and calculating a component value in the casting direction of the heat flux on the working surface;
On the basis of the component value in the casting direction of the heat flux on the operating surface calculated by the calculating means, a hot water surface level detecting means for detecting the hot water surface level,
Calibration means for calibrating the eddy current type water level meter based on the level level detected by the level level detecting means,
Control means for controlling the flow rate of molten steel from the immersion nozzle based on the level of hot water after calibration detected by the vortex type hot water level meter ,
The molten metal surface level detecting means determines that the position at which the component value in the normal direction of the molten metal surface opposite to the casting direction of the heat flux on the operating surface calculated by the calculating device is the maximum is the molten metal surface level. A control device for the flow rate of molten steel in a continuous casting mold.

A program for controlling the flow rate of molten steel in a continuous casting mold,
An input process for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation process for solving a heat transfer inverse problem using the input measurement value of the temperature detection means and calculating a component value in the casting direction of the heat flux on the working surface;
Based on the component value in the casting direction of the heat flux on the calculated operating surface, a hot water surface level detection process for detecting the hot water surface level ,
Based on the detected hot water level, the computer executes a control process for controlling the molten steel flow rate from the immersion nozzle ,
In the molten metal surface level detection process, the position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculation process is determined as the molten metal surface level. A featured program.

A program for controlling the flow rate of molten steel in a continuous casting mold,
An input process for inputting measurement values of a plurality of temperature detection means arranged and embedded in the casting direction of the continuous casting mold,
A calculation process for solving a heat transfer inverse problem using the input measurement value of the temperature detection means and calculating a component value in the casting direction of the heat flux on the working surface;
Based on the component value in the casting direction of the heat flux on the calculated operating surface, a hot water surface level detection process for detecting the hot water surface level ,
A calibration process for calibrating the eddy current level meter based on the detected level level;
Based on the calibrated molten metal level detected by the vortex flow meter, the computer executes a control process for controlling the molten steel flow rate from the immersion nozzle ,
In the molten metal surface level detection process, the position where the component value in the normal direction of the molten metal surface that is opposite to the casting direction of the heat flux on the operating surface calculated in the calculation process is determined as the molten metal surface level. A featured program.