Two-dimensional dynamic simulation of the thermal state of ladles

Abstract

A two-dimensional mathematical model of steelmaking ladles is presented. The model can be used as a design tool, by which a number of variables such as holding time, material choice, and refractory layer thicknesses can be studied with regard to their influence on the steel temperature evolution during casting. In addition, the model can act as a decision support and as a basis for automation of temperature control. Temperature measurements from an operational steelmaking ladle are compared to simulation results obtained with the model, demonstrating its feasibility and applicability to steelmaking. I. BACKGROUNDwas done by numerical integration of the heat-conduction equation for the ladle wall. [4,5,[11][12][13][14] Due to the intricate IN modern steelmaking, after the introduction of the conboundary-condition changes for the equation as the ladle tinuous casting process and new refractory materials, steel cycles through various stages of secondary metallurgy, onetemperature control within the narrow bounds called for by dimensional solutions at different height positions in the quality requirements has become increasingly demanding.refractory have been adopted as a sufficient means for steel As holding times for steel in the ladle have increased and temperature prediction. [14,15] Although this approach is process logistics often over-rule thermal-and energyappropriate for on-line simulation, more powerful modeling efficiency aspects, improved strategies for heat-loss estimaand simulation tools are required to achieve a deeper undertion for the steel are necessary. Contemporary refractory standing of thermal phenomena in the ladle cycle, e.g., materials, with improved durability and longer campaign through parametric studies. life, are thermally inferior to traditional brick material, i.e.,Another application of thermal modeling of metallurgical their heat conductivity and specific heat are larger, resulting ladles is the design of refractory configurations. [16,17,18] This in increased heat losses from the steel. Over multiple ladle has been a growing field, with the advent of new materials cycles, this can also lead to unacceptably high shell temperacapable of withstanding longer campaigns and higher temtures for the ladle, introducing problems with shell buckling peratures but, unfortunately, having less-advantageous and lining separation. thermal properties. Traditionally, engineering of ladle refractories has been done by confirming, with steady-state calculations, that the refractory and shell temperature stayed II. INTRODUCTION within permissible temperature bounds. Although this Over the years, a number of thermal models for ladle mostly produced acceptable lining-material assemblies, systems has been presented. Early contributions feature simsince the steady state would give substantially overestimated ulation of heat losses and refractory temperature profiles on temperatures, it was hard to foresee long-term effects over an analog computer. [1,2] More-recent approaches range in multiple ladle cycl...

Numerical Simulation of Heat Transfer Phenomenon in Steel Making Ladle

“…4) Investigators also developed some simple models to predict the steel temperature in the ladle. [5][6][7][8][9][10] Since most of these models were 2-D, the effect of radiation exchange between surfaces of ladles was not explicitly taken care of. The phenomenon of thermal stratification leads to temperature difference between bulk and outgoing steel during teeming.…”

“…However, research investigation in the past also had considered the influence of the temperature gradient in the molten steel on the bulk heat losses as minor. 7) Therefore, the convection effect during tapping and holding period can be considered separately, if required. The CFD technique is used for generating the thermal profile of ladle and molten steel in the present model.…”

Neural network to diagnose lining condition

“…Lined equipment, including torpedo ladle cars, hot-metal cars and steel ladles are considered to be critical equipment at heavy industry and machinery building facilities. Such equipment is classified as critical since consequences of accidents involving such equipment lead to multimillion losses for the enterprise and in some cases to human deaths, which is proved by a number of sources [1][2][3]. In order to prevent accidents with such type of equipment and maintain industrial safety at the production facility, a growing number of diagnostic operations and technologies to control technical condition of lined equipment are applied in production units which, in turn, require development of new and improvement of existing technical means and information technologies Nowadays there are different automated systems to monitor, diagnose and operate critical equipment at production units [4][5][6].…”

A Statistical Model for Predicting the Liquid Steel Temperature in Ladle and Tundish by Bootstrap Filter

“…The former, mainly based on the thermodynamics, has long history and there are many studies. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] However, physical models require complex numerical techniques like finite difference methods (FDM) [1][2][3][4][5][6][7][8][9][10][11][12] and finite element methods (FEM). 13,21) Moreover, physical calculation of liquid steel temperature requires the simulation of thermo-fluid behaviors like vortex and convection, which is time-consuming.…”