Converter Blowing Control via Pre-blowing Temperature Estimation
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Solution Overview
Problem
Current converter blowing control methods face challenges in accurately controlling the temperature of molten steel at the end of blowing due to inaccuracies in heat balance calculations, particularly in determining the sensible heat of the molten iron, leading to errors in static and dynamic control.
Innovation Solution
The method involves estimating the pre-blowing molten iron temperature by considering temperature changes during charging and incorporating this estimate into the heat balance calculation, using data from past blowings to determine post- and pre-charging temperature changes, and employing non-contact optical methods for accurate temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the molten iron temperature measured during charging is directly used as the charged molten iron temperature in heat balance calculation, then the measurement is simple, but the control accuracy of molten steel temperature is insufficient due to temperature changes during charging and before blowing
Solution Approach 1:
The patent applies preliminary action by estimating the pre-blowing molten iron temperature in advance before the blowing process begins. The system calculates temperature changes during charging (from charging start to charging end) and from charging end to blowing start, then uses these preliminary estimations as the charged molten iron temperature in heat balance calculations, improving temperature control accuracy without complex additional measurements
Solution Approach 2:
The patent implements feedback by using actual sublance measurements taken during blowing to correct and refine the estimated pre-blowing molten iron temperature. The system compares the estimated temperature with actual measurements and adjusts subsequent estimations based on this feedback, creating a closed-loop control system that continuously improves temperature control accuracy
2Measurement precision
If exhaust gas information is used to estimate decarbonize-oxygen efficiency and improve temperature estimation, then the reaction heat from decarburization is accurately reflected, but other factors affecting molten steel temperature are not fully considered
Solution Approach 1:
The patent merges multiple temperature estimation approaches by combining exhaust gas-based decarburization heat estimation with direct temperature change measurements during charging. The system integrates these different measurement sources and combines them with heat balance calculations to create a comprehensive temperature estimation that considers all major factors affecting molten steel temperature
3Manufacturing precision
If the charged molten iron temperature is inaccurately determined in heat balance calculation, then the static control error is large, but dynamic control cannot fully correct this error
Solution Approach 1:
The patent applies preliminary action by performing accurate temperature estimation before blowing begins, using measured temperature changes during charging and from charging end to blowing start. This preliminary temperature determination is then used in static control heat balance calculations, significantly reducing initial control errors and enabling both static and dynamic control to work more effectively together
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of heat balance calculations, enabling precise control of molten steel temperature at the end of blowing to target values.
Implementation Method 1
a radiation thermometer and time information, an amount of temperature drop of molten steel
Implementation Method 2
employing non-contact optical methods for accurate temperature measurement
Data Source
AI summary
A converter blowing control method includes: calculating, by heat balance calculation and material balance calculation, an amount of oxygen supplied and an amount of a cooling material or a rising heat material charged to control a temperature and a component concentration of molten steel at end of blowing in a converter to target values; controlling the blowing in the converter based on the calculated amount of oxygen supplied and the calculated amount of a cooling material or a rising heat material charged; estimating a pre-blowing molten iron temperature that is a temperature of molten iron used as a raw material for blowing to be a target of the heat balance calculation, charged into the converter, and is in a state immediately before start of the blowing; and using the estimated pre-blowing molten iron temperature as a charged molten iron temperature in the heat balance calculation.