JP-7856226-B1 - Method for estimating molten steel temperature, method for controlling molten steel temperature, and method for manufacturing molten steel.

JP7856226B1JP 7856226 B1JP7856226 B1JP 7856226B1JP-7856226-B1

Abstract

The molten steel temperature estimation method estimates the molten steel temperature in the process of handling molten steel in the steelmaking process. The molten steel temperature estimation method includes the steps of: dividing the process from start to finish into multiple sections based on at least one molten steel temperature measurement point during the process; measuring the molten steel temperature at the start of each of the multiple sections; estimating the change in molten steel temperature in the current section to which the current time belongs, and the change in molten steel temperature in the sections after the current section, based on a molten steel temperature estimation model constructed for each of the multiple sections; and estimating the molten steel temperature at the end of the process by combining the estimated change in molten steel temperature in the current section and the change in molten steel temperature in the sections after the current section.

Inventors

大東祐汰
溝端圭介

Assignees

ＪＦＥスチール株式会社

Dates

Publication Date: 20260511
Application Date: 20250609
Priority Date: 20240816

Claims (7)

A method for estimating the molten steel temperature in the molten steel processing in the steelmaking process, The steps include dividing the process from start to finish into multiple sections based on at least one point in time during the process at which the molten steel temperature is measured, The steps include measuring the molten steel temperature at the start of each of the aforementioned multiple sections, Based on multiple molten steel temperature estimation models constructed for each of the aforementioned multiple intervals, the steps include estimating the change in molten steel temperature in the current interval to which the present time belongs, and the change in molten steel temperature in the intervals after the current interval, The steps include: estimating the molten steel temperature at the end of the process by combining the estimated change in molten steel temperature in the current section , the change in molten steel temperature in the section after the current section , and the molten steel temperature at the start of the current section; Includes, The time at which the molten steel temperature is measured is a predetermined time. In the aforementioned molten steel temperature estimation model, The inputs are: operation information of the preceding process executed before the said process; operation information up to the previous section in the said process; planned operation information for the section in which the molten steel temperature estimation model was constructed; and equipment information for the said process. A method for estimating molten steel temperature, wherein the output is the change in molten steel temperature from the start to the end of the section in which the molten steel temperature estimation model was constructed .
The molten steel temperature estimation method according to claim 1, wherein the parameters of the molten steel temperature estimation model are determined based on past operational performance.
The operational information of the preceding process performed before the aforementioned process includes at least one of the molten steel information, operational amount information, and processing time information in the preceding process. The operational information up to the previous section in the aforementioned process includes at least one of the molten steel information, operational volume information, and processing time information up to the previous section. The operational schedule information for the section in which the molten steel temperature estimation model is constructed includes at least one of the operational volume information and processing time information for the section in which the molten steel temperature estimation model is constructed . The method for estimating molten steel temperature according to claim 1 , wherein the equipment information for the processing includes information regarding the usage history of the ladle used for the processing and information regarding the measured temperature of the ladle.
The aforementioned process is a secondary refining process, The pre-process performed before the aforementioned process is a primary refining process. The operational information of the preceding process performed before the aforementioned process includes at least one of the weight of the molten steel and the temperature of the molten steel at the end of the preceding process . The operational schedule information for the section where the molten steel temperature estimation model was constructed includes at least one piece of information: the amount of auxiliary materials input, the amount of oxygen blown in, and the processing time. The molten steel temperature estimation method according to claim 3, wherein the equipment information for the processing includes at least one of the measured temperature information obtained by measuring the ladle used for the processing when it is empty, the time when the ladle is empty from the time when the molten steel received in the previous processing is discharged until the molten steel received in the current processing is received, and the time from the end of the immediately preceding secondary refining process to the start of the said secondary refining process.
The molten steel temperature estimation method according to claim 4 , wherein the molten steel temperature estimation model is a neural network model in the period immediately after the start and immediately before the end of the secondary refining process, and a linear regression model in the other periods.
A molten steel temperature control method that calculates a molten steel temperature adjustment amount for adjusting the molten steel temperature so that the difference between the molten steel temperature at the end of the process, estimated by the molten steel temperature estimation method according to any one of claims 1 to 5, and the target temperature of the molten steel at the end of the process is within a predetermined range.
A method for producing molten steel, comprising adjusting the molten steel temperature using the molten steel temperature control method described in claim 6 .

Description

This disclosure relates to a method for estimating molten steel temperature, a method for controlling molten steel temperature, and a method for manufacturing molten steel. The steelmaking process involves refining and casting. Refining involves controlling the component concentration of molten steel to a desired range. Casting involves solidifying the molten steel. To ensure these processes run smoothly, it is crucial to control the molten steel temperature within an appropriate range. The refining process involves primary and secondary refining. One of the main roles of secondary refining is to regulate the molten steel temperature. When adjusting the molten steel temperature during secondary refining, the operator typically measures the molten steel temperature during processing as needed and estimates the subsequent change in temperature. If the difference between the estimated temperature and the target temperature is large, the operator then performs operations to heat or cool the molten steel. Methods for estimating changes in molten steel temperature include methods based on physical models and methods based on statistical models. For example, Patent Document 1 discloses a method for estimating changes in molten steel temperature based on a physical model. Also, for example, Patent Documents 2 and 3 disclose methods for estimating changes in molten steel temperature based on statistical models. Japanese Patent Publication No. 2016-180127Japanese Patent Publication No. 2012-57195Japanese Patent Application Publication No. 8-3621 This figure shows an example of a molten steel temperature control device that performs a molten steel temperature estimation method and a molten steel temperature control method according to one embodiment of the present disclosure.This is a block diagram showing an example of the configuration of a molten steel temperature control device according to one embodiment of the present disclosure.This figure shows an example of how the refining process is divided into two sections.This figure shows an example of how the refining process is divided into three sections.This flowchart shows an example of a molten steel temperature estimation method and a molten steel temperature control method according to one embodiment of the present disclosure.This figure compares the estimation error of the molten steel temperature change between a comparative example and this embodiment. The embodiments of this disclosure will be described below with reference to the drawings. Figure 1 shows an example of a molten steel temperature control device that implements a molten steel temperature estimation method and a molten steel temperature control method according to one embodiment of the present disclosure. Figure 1 shows an example of a secondary refining process in the steelmaking process. In Figure 1, the secondary refining apparatus 1 performs the secondary refining process on the molten steel in the ladle 2. The molten steel temperature control device 10 estimates the molten steel temperature for molten steel undergoing secondary refining. Based on the estimated molten steel temperature, the molten steel temperature control device 10 determines a molten steel temperature manipulation amount to adjust the temperature and controls the molten steel temperature. In this embodiment, the molten steel temperature estimation method and molten steel temperature control method are described using the application of the molten steel temperature control method to a secondary refining process as an example. However, this is merely an example, and the molten steel temperature estimation method and molten steel temperature control method according to this embodiment can be applied to any process in the steelmaking process that handles molten steel. For example, the molten steel temperature estimation method and molten steel temperature control method according to this embodiment can also be applied to a primary refining process. Here, in the primary refining process, the molten steel temperature rises by approximately 300°C due to desilicate and decarburization reactions, whereas the change in molten steel temperature in the secondary refining process is 20 to 40°C. Therefore, the required accuracy of molten steel temperature estimation is higher in the secondary refining process than in the primary refining process. For this reason, the molten steel temperature estimation method and molten steel temperature control method according to this embodiment can be more effective when applied to a secondary refining process. Figure 2 is a block diagram showing an example of the configuration of a molten steel temperature control device 10 according to one embodiment of the present disclosure. The molten steel temperature control device 10 may be a general-purpose computer such as a workstation or personal computer, or it may be a dedicated computer configured to function as a molten steel temperature control devi