Numerical modeling of multiphase plasma/soil flow and heat transfer in an electric arc furnace

Paik, Seungho; Nguyen, Hoa D.

doi:10.1016/0017-9310(94)00248-t

Cited by 15 publications

(21 citation statements)

References 15 publications

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“…The arc radius, R a , can be easily obtained from This means that before the impingement zone is reached, a unique or dimensionless B Q field expressed in dimensionless form can be obtained using Eqs. (6) and (7) since B 0 max and R a are available through Eqs. (9) and (5), due to the unique arc shape behavior for the range of conditions explored in this study.…”

Section: Dimensionless Representation Of the Arcmentioning

confidence: 99%

“…However, their arc model was too simplified to be realistic, especially in representing the electromagnetic phenomena. After this work, only a few attempts have been published in the literature [5][6][7] but unfortunately no radically new contributions have been made to this field of modeling since the work of McKelliget and Szekely appeared more than 25 years ago.…”

Section: Introductionmentioning

confidence: 99%

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Mathematical Modeling of a DC Electric Arc-Dimensionless Representation of a DC Arc

Ramírez

Trápaga

2003

ISIJ International

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A mathematical model presented in previous publications is used to describe fluid flow, heat transfer and electromagnetic phenomena in the arc region of a Direct Current Electric Arc Furnace (DC-EAF). The effects of the arc current and the arc length on the arc characteristics and arc bath interactions are analyzed in a rather generalized way. This analysis leads to the conclusion that the arc behaves in such a way that when the arc shape (defined with the location of the 10 000 K isotherm) is plotted in the appropriate dimensionless form a unique arc expansion is achieved. This unique expansion (only restricted to arcs burned between graphite electrodes in air and outside the region where the arc jet impinges on the bath surface) gives the possibility to provide single dimensionless arc characteristics regardless the values of the arc current and arc length. These dimensionless correlations represent the main finding of this work and they allow means to estimate the important characteristics of the arc under different operational conditions without the need to run complex numerical calculation. The dimensionless characteristics of arc expressed in simple algebraic forms can be used for this purpose employing a pocket calculator.

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Section: Dimensionless Representation Of the Arcmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mathematical Modeling of a DC Electric Arc-Dimensionless Representation of a DC Arc

Ramírez

Trápaga

2003

ISIJ International

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“…The average arc temperature and pressure are used to calculate the arc density and the average velocity that are needed to approximate the arc energy dissipation. The average temperature is considered to be 16 136 K 5,22) and the average pressure is assumed to be 1 200 kPa.…”

Section: Mhd Resultsmentioning

confidence: 99%

“…• the local thermodynamic equilibrium (LTE) is assumed, meaning that electrons and positive ions are at the same temperature; 7) therefore, plasma acts as a continuous environment, 22) • cylindrical shape is assumed for plasma arc region, even though in practice the shape of the arc is similar to cone, • temperature and current are considered uniform over the entire plasma region. The CAM model addresses the following types of heat transfer as a function of arc length and arc current: radiation, convection and electron flow, which are mathematically described by Eqs.…”

Section: Modellingmentioning

confidence: 99%

Low Computational-complexity Model of EAF Arc-heat Distribution

et al. 2015

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The paper presents a computational model and the corresponding algorithm for estimating the arc energy distribution to conductive, convective and radiative heat transfer in an electric arc furnace (EAF). The proposed algorithm uses channel arc model (CAM) in order to compute the distribution of the arc energy through empirical equations (to approximate arc radius), ideal gas law (to approximate arc density) and results of magneto-hydro-dynamic (MHD) models (to approximate arc pressure, temperature and velocity). Results obtained using the proposed algorithm are comparable with other similar studies; however, in contrast to other arc-energy distribution models, this model requires only two input variables (arc length and arc current) in order to calculate the energy distribution. Furthermore, simple algebraic equations used in the algorithm ensure minimal computational load and consequently lead to short calculation times which are approximately one hundred thousand (100 000) times smaller than solving the MHD model equations, making the algorithm suitable for real-time applications, such as smart monitoring and model-based control. The algorithm has been validated by two different approaches. First, the simulation results have been compared to a study dealing with arc-heat distribution in plasma arc furnace; and second, the proposed arc module has been integrated into the frame of a comprehensive EAF model in order to estimate the EAF temperature levels and compare them with operational EAF measurements. Both validations show high levels of similarity with the comparing data.KEY WORDS: arc current; arc heat distribution; arc length; channel arc model; EAF.approximately 75-85% of the total energy in low to medium power furnaces and approximately 50-60% of the total energy in ultra-high power furnaces (UHP).3) Implementing an accurate arc module in a comprehensive model-based EAF control, which ensures optimal control of arc length and slag height can lead to substantial energy saving and associated cost reduction. If a total energy reduction in a 200 ton UHP EAF with approximate annual production of 675 000 tones is 50 kWh/ton, with an assumption of 25 kWh/ton being the electrical energy, with the price of 10 $Cent/kWh, total annual energy savings will be equivalent to 1.7 million $ per year.It is known that the heat generated by the arcs is dissipated into the furnace by all three mechanisms of heat transfer (convection, conduction and radiation); however, the amount of the heat, transferred by each mechanism varies according to several factors, such as arc length, arc current, slag height, stage of melting etc. Development of a computational model of the arc, which allows estimation of the arc-heat distribution should therefore include all three types of heat transfer mechanisms, which can also be used to obtain the overall energy balance of the EAF. Application of such models may provide appropriate tools for optimizing the energy flow or use of model-based control systems in the EAFs.

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“…The most important zone of the heating chamber is the electric arc. In previous studies, [1][2][3][4][5][6][7][8] the arc is often divided into three distinct regions: the arc column and the two near-electrode regions.…”

Section: Introductionmentioning

confidence: 99%

Numerical Modelling of an Anodic Metal Bath Heated with an Argon Transferred Arc

et al. 2003

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A new 3-D model has been developed to describe the interaction between a transferred electric arc and a liquid metal bath, and has been used to simulate a pilot axisymmetrical transferred arc furnace operating in the EDF Research and Development laboratory.This model enables calculations of the flow patterns, temperature distribution and electromagnetic fields in both the arc and the bath. The Navier-Stokes equation coupled with the electromagnetic relations are solved in each domain using a finite volume method. The source term in the radiative energy equation is modeled using the radiative transfer method in order to take into account the strong temperature variations in the electric arc. The transport and condensation of metal vapour in the arc domain are considered by solving a conservation equation for the vapour mass fraction. The arc flow calculation at the bath surface uses a one-dimensional sheath model taking account of the metal vapour, in order to ensure the coupling between the plasma and the bath by evaluating the boundary conditions at the arc/bath interface. The calculations were performed for an arc length of 0.25 m.Realistic predictions are obtained for the electrical, dynamic and thermal behaviour of the plasma and liquid metal, and also for the arc voltage. The results indicate that the effects of the arc impact and Lorentz forces are not sufficient to induce effective mixing throughout the metal bath, leading to a marked thermal stratification in the liquid metal. In the bath, the liquid/solid interface has been determined by calculations.

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Numerical modeling of multiphase plasma/soil flow and heat transfer in an electric arc furnace

Cited by 15 publications

References 15 publications

Mathematical Modeling of a DC Electric Arc-Dimensionless Representation of a DC Arc

Mathematical Modeling of a DC Electric Arc-Dimensionless Representation of a DC Arc

Low Computational-complexity Model of EAF Arc-heat Distribution

Numerical Modelling of an Anodic Metal Bath Heated with an Argon Transferred Arc

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