Application of fuzzy logic control for continuous casting mold level control

Dussud, M.; Galichet, Sylvie; Foulloy, Laurent

doi:10.1109/87.664191

Cited by 62 publications

(31 citation statements)

References 10 publications

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“…Many factors such as inaccuracy of mold level sensor, disturbance of liquid steel flow inside the mold and volume change of liquid steel in the mold could cause the MLH. The effects of mold level control systems [5][6][7] and the flow of liquid steel in the mold [8][9][10] on MLH have been studied for many years, and many solutions have been found out in order to reduce their influence on MLH. The flow behavior of liquid steel in the mold can be subdivided into three kinds such as inflow of liquid steel from tundish, outflow due to downward movement of strand with casting speed and liquid steel flow inside the solidified shell.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Mold Level Hunching by Unsteady Bulging during Thin Slab Casting.

et al. 2002

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In order to analyze the phenomenon of mold level hunching (MLH) during thin slab casting process, the variation of the mold level and the bulging of strand were measured and analyzed using Fast Fourier Transform (FFT) spectrum analysis. Both of mold level hunching and bulging had the same frequency and the specific frequency corresponded to the main roll pitch of the thin slab caster. The unsteady bulging was found to be a main reason of mold level hunching. The unsteady bulging profile through the full range of the caster and the height of mold level hunching were calculated using a heat transfer model and a continuous beam model. The effects of process variables on mold level hunching and the process condition of reducing mold level hunching were studied. The amount of mold level hunching increased as unsteady bulging increased due to the hunching of casting speed. An aperiodic roll pitch between segments could be effective in reducing mold level hunching.KEY WORDS: mold level hunching (MLH); unsteady bulging; FFT analysis; continuous beam model; thin slab casting; aperiodic roll pitch.

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Section: Introductionmentioning

confidence: 99%

Analysis of Mold Level Hunching by Unsteady Bulging during Thin Slab Casting.

et al. 2002

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“…This controller was integrated with a PID controller resulting in a global control architecture. It was experimentally shown to be satisfactory [110].…”

Section: E Steel Process Industrymentioning

confidence: 93%

Industrial applications of soft computing: a review

Dote

Ovaska²

2001

Proc. IEEE

136

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“…[2][3][4][5][6] Eddy-current sensors are preferred because they provide accurate measurements and are easy to put into practice. Floating sensors or radiometric sensors may also be used.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Analysis of the Free Surface in a Water Model of a Slab Continuous Casting Mold

et al. 2005

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The flow patterns prevailing at the free-surface in a water model of a slab continuous casting mold using several water flow rates and entry nozzle submergence depths are experimentally and numerically studied in this work. The experimental study was carried out using an one-third scale cold water model, constructed in accordance with the Froude similarity criterion. Water level measurements were carried out with ultrasonic distance sensors and recorded in a computer. Numerical simulations were made with a commercial computational fluid dynamics software. It was found that free-surface oscillations are composed by several periodic components. There exists a fundamental periodic frequency of 1.2 Hz. Besides, there exist two other frequencies of 1.8 and 2.1 Hz whose contribution to the free surface dynamic behavior depend on the spatial position and on the process parameters, namely, the volumetric flow rate and the submerged entry nozzle (SEN) submergence depth. In accordance with the obtained results, several recommendations about operating policies of actual industrial casters are made.KEY WORDS: free surface velocity; mold flow; power density spectrum; slab continuous casting; submerged entry nozzle.well-known Navier-Stokes equations, which in vectorial form are expressed as follows 8,10) Given that the experiments are carried out isothermally, the energy equation is not considered. The K-e turbulence model was selected for mathematical modeling, which is described by the following expressions: ... (4) In the above equations K is the turbulent kinetic energy, e is dissipation rate of K. s K , s e , C 1 and C 2 are constants whose values are 1.0, 1.3, 1.44 and 1.92 respectively.8) The fluid viscosity must be corrected for turbulence in the Navier-Stoke equations employing an effective viscosity m eff ϭm l ϩm t , where m l is the laminar viscosity and m t is the turbulent viscosity. The latter can be determined as follows: (5) where C m ϭ0.09 is a constant. The boundary conditions in the mathematical model were those recommended by Thomas et al. 8) and are as follows: Inlet turbulence parameters at the inlet were Kϭ0.044 m 2 s Ϫ2 and eϭ1.00 m 2 s Ϫ3. At the outlet, the boundary condition was fixed in such a way that the mass balance was satisfied.A commercial CFD software was employed for numerical solving of the above mathematical model. A two-dimensional mesh with 32 500 nodes was created with a time step of 0.001 s. A personal computer with 1 GB of RAM memory and 3.0 GHz CPU was utilized for the numerical simulations. A run for 70 s of real time required a CPU time of approximately 5 h. In order to track the free surface profile, two-phase flow was considered and the Volume-of-fluid (VOF) model 10) was chosen for tracking of the air-water interface. Physical ModelingA plastic one-third scale water model was designed and constructed in accordance with the Froude similarity criterion. Froude criterion guarantees that the water model is similar to the industrial caster mold from the geometrical and dynamical...

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Application of fuzzy logic control for continuous casting mold level control

Cited by 62 publications

References 10 publications

Analysis of Mold Level Hunching by Unsteady Bulging during Thin Slab Casting.

Analysis of Mold Level Hunching by Unsteady Bulging during Thin Slab Casting.

Industrial applications of soft computing: a review

Experimental and Numerical Analysis of the Free Surface in a Water Model of a Slab Continuous Casting Mold

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