Modeling of Radiative Heat Transfer in an Electric Arc Furnace

The determination of view factors (VF) is a central component of the heat transfer model in comprehensive electric arc furnace process models. Due to the complex nature of the process, simplifying assumptions are necessary to allow the efficient estimation of VF. These simplifications mainly deal with the geometrical representation of the furnace and the methods to calculate the resulting VF. Such assumptions have been applied in several studies; however, while the results of the complete process models have been validated extensively, the calculated VF have not been examined in detail. Herein, two methods of calculating VF based on a geometry similar to that used in the process models proposed by MacRosty et al., Logar et al., and Meier et al. are presented and validated by comparing the results obtained using a commercial computational fluid dynamics software. The number of assumptions and simplifications is reduced when compared with previously published results and both methods are proven to be accurate while remaining computationally efficient enough for the application in process models for online applications and process optimization, where fast execution is necessary.

Section: Introductionmentioning

confidence: 99%

Calculation of View Factors in Electric Arc Furnace Process Modeling

Hay

Hernández

Roberts

et al. 2020

“…The black body assumption of plasma surface is limiting the accuracy of the absorptivity models of the EAF atmosphere, especially in the areas close to the arc. To achieve more accurate modeling of the heat transfer, the wavelength‐dependent arc emissivity model could be utilized with a weighted‐sum‐of‐gray‐gases model for the EAF atmosphere as proposed by Opitz et al [ 44 ]…”

Section: Discussionmentioning

confidence: 99%

“…Meier et al [ 13,36 ] also based their work on Logar's model, adding the electrode and the gas phase including dust to the radiative heat transfer calculations. Opitz et al [ 44 ] again adopted Logar's estimation of view factors and introduced several adjustments such as the impact of gas and dust on the radiative heat transfer and a more detailed representation of the scrap batch with several individual sections.…”

Section: Heat Transfermentioning

confidence: 99%

See 1 more Smart Citation

A Review of Mathematical Process Models for the Electric Arc Furnace Process

Hay

Visuri

Aula

et al. 2020

The electric arc furnace is the main process unit in scrap‐based steelmaking. Owing to its importance, numerous mathematical models for predicting the course of the electric arc furnace process have been developed. This article reviews mathematical process models proposed in the literature, identifying the most common modeling approaches, and uses mathematical descriptions for the main phenomena. Furthermore, the validation of such models is discussed in detail. Finally, the article identifies gaps in the existing knowledge and provides suggestions for the further development of mathematical process models.

“…The radiative heat transfer module described in Fathi et al counts all surfaces (excluding the arc ) as gray bodies and utilizes Stefan‐Boltzman law to compute the radiosity of surfaces, as described by Equation . In contrast to some studies, such as Opitz et al, emission and absorption of off‐gas is neglected.

(J_{i} - {normalσ}_{B} T_{i}^{4}) \frac{{NA}_{i} ϵ_{i}}{1 - ϵ_{i}} + \sum_{j, j \neq i} ({italicJ}_{italici} - {italicJ}_{italici}) {italicNA}_{italici} {italicVF}_{italicij} = 0.

…”

Section: Modelingmentioning

confidence: 95%

EAF Heat Recovery from Incident Radiation on Water‐Cooled Panels Using a Thermophotovoltaic System: A Conceptual Study

Saboohi

Fathi

Škrjanc

et al. 2018

In this paper, a conceptual study and quantification of using a thermophotovoltaic system (TPV) to convert incident radiation on furnace panels to electrical energy is presented. In typical electric arc furnaces (EAF), a considerable amount of energy is wasted during the melting process, that is, steel enthalpy, off-gas extraction, vessel cooling, slag enthalpy, and others. Although a remarkable share of the energy is wasted in circulating water, the contained exergy is simply too low to be considered for heat recovery (under 0.5% of input exergy) in comparison to energy content of the extracted gasses and slag. In the performed study, a TPV power output is calculated as a function of arc length, slag and bath height, zone temperatures, and emissivities. Two major changes to the existent EAF model were performed in order to estimate the TPV efficiency, that is, 1) the radiative heat transfer module has been re-developed to allow calculation of the incident radiation on the TPV, 2) the model has been extended with a TPV module, which is used to estimate the electricity produced by the TPV. The effects of TPV capacity, its distance from the slag layer and input regime on generated electrical energy are studied. The results have shown that a typical EAF, equipped with TPV system, can reduce average energy consumption by 4.8 kWh ton À1 , which corresponds to approximately 0.8% overall efficiency improvement. Moreover, the capacity factor of the installed TPV is predicted at 54% over a period of one year.