Modeling of Radiative Heat Transfer in an Electric Arc Furnace
- PDF / 1,682,372 Bytes
- 15 Pages / 593.972 x 792 pts Page_size
- 18 Downloads / 325 Views
RODUCTION
RADIATION is an important means of heat transfer inside an electric arc furnace (EAF). The radiative heat transfer depends strongly on the geometrical configuration of the participating components. However, the geometrical configurations are continuously changing inside an electric arc furnace in the course of a heat. Due to this difficulty and in contrast to its importance only few EAF models are reported in literature which take radiative heat transfer into account. In a previous publication, the authors presented a system model of a complete EAF plant without considering radiation.[1] Meanwhile, radiative heat transfer has been added to the model. This paper describes the underlying concept and compares simulation results with and without radiation. To our knowledge, among all published system models of the EAF process only the models of MacRosty and Swartz[2] and of Logar et al.[3] took radiation into account as an independent form of heat transfer. Both models were based on a simplified geometrical concept: A steadily increasing frustum of a cone represents the changing geometry through the
FLORIAN OPITZ and PETER TREFFINGER are with the Offenburg University of Applied Sciences, Badstr. 24, 77652 Offenburg, Germany. Contact e-mail: florian.opitz@hs-offenburg.de JU¨RGEN WO¨LLENSTEIN is with the University of Freiburg, Georges-Ko¨hler-Allee 102, 79110 Freiburg, Germany and also with the Fraunhofer Institute for Physical Measurement Techniques IPM, Heidenhofstr. 8, 79110 Freiburg, Germany. Manuscript submitted February 20, 2017.
METALLURGICAL AND MATERIALS TRANSACTIONS B
ongoing heat, namely the descent of the scrap pile and the exposure of the walls. Furthermore, the models only considered radiative heat transfer between the electric arcs and the other surfaces. Originally, the gas phase and the dust radiation were not taken into account. However, recently Meier et al.[4] expanded the model of Logar et al. by gas radiation. Alexis et al.[5] presented a detailed CFD model to simulate the radiative heat transfer from the electric arc in a DC furnace. The model is implemented using fundamental mathematical relations in order to understand the underlying physical phenomena. The authors state that their model is useful to determine the role of different operating parameters and to calculate the heat efficiency of different operating conditions. Another simulation was carried out by Guo and Irons,[6] who had examined the radiation inside an electric arc furnace. The authors limit this study to the case of flat bath and surface radiation. Gas radiation was not considered. The model allows the estimation of radiative heat flow rates from the arcs as well as the temperature distribution inside the furnace. Jordan et al.[7] investigated experimentally the characteristics of heat transfer and mechanisms of electrode erosion in a one-phase experimental furnace. They concluded that 28 pct of the arc’s power is transferred by direct radiation and another 6 pct by radiation of the arc’s flame. Table I summarizes the above mentione
Data Loading...
