Modeling and Validation of the Radiative Heat Transfer in an Electric Arc Furnace

Abstract

This paper presents an approach to the mathematical modeling and validation of the radiative heattransfer processes in an electric arc furnace (EAF). This radiative heat transfer represents an important part of the complete EAF model, which is further composed of electrical, hydraulic, thermal, chemical and mass-transfer sub-models. These have already been addressed in our previous publications. It is well known that during the operation of an EAF all three types of heat transfer (conductive, convective and radiative) are present; however, a great portion of the heat is transferred between the surfaces by means of radiation. The model presented in this work uses a simplified internal geometry of the EAF to represent the relations between the defined EAF zones and is developed in accordance with fundamental thermodynamic laws. The parameters of the model were fitted using the geometrical relations in the EAF; theoretically, using the conclusions from different studies involved in EAF modeling; and experimentally, using the measured temperatures on the furnace roof and the water-cooled panels. Since the radiative heat mostly represents a negative impact on the furnace roof, walls and linings, the obtained model represents an important part of the complete EAF. The presented results show satisfactory levels of similarity between the measured and simulated temperatures of the roof and water-cooled panels, which suggest that the presented model is relatively accurate and follows the fundamental laws of thermodynamics. Possessing such a model is of special importance when enhancing the EAF process using different optimization techniques, since the radiative impacts on the furnace need to be taken into the account in order to maintain or reduce the wear on the furnace lining.

Modeling and Simulation of the Off-gas in an Electric Arc Furnace

“…The molar reaction rate r can be determined by Eq. [4], while the equilibrium constant K c is determined by the forward and backward reaction rate constant according to Eq. [5].…”

“…Natural gas, which consists mainly of CH 4 , is injected through the burner system (x15 d3 ). The CH 4 is assumed to react in three different ways (x15 d4 , x15 d5 , and x15 d6 ) and, finally, CH 4 is post-combusted (x15 d7 ).…”

“…This empirical factor is calculated according to the coverage of the burner nozzle openings by scrap (e.g., after scrap charging). In this case, only an insufficient mixing of the two gases CH 4 and O 2 is assumed, which leads to an incomplete reaction of CH 4 . K O 2 ÀCH 4 Àinj is calculated with Eq.…”

“…In times of continuously growing computational capacity, the complexity of the dynamic process simulation models has increased due to the consideration of more and more phenomena. Logar et al [2][3][4] presented a comprehensive deterministic EAF model, which is based on fundamental physical and mathematical equations. The model includes all main thermal, chemical, and mass transfer phenomena in the EAF.…”

“…Therefore, in addition to CO, CO 2 , N 2 , O 2 , and CH 4 , the components H 2 , H 2 O, and CH 4 are also included in the gas phase of this study. The components are considered in chemical reactions for post-combustion, major equilibrium reactions, and dissociation.…”