Results are presented from an analysis of the motion of gas flows created by fuel-burning devices in existing electric-arc steelmaking furnaces and recommendations are made on how to efficiently arrange this equipment in the furnace. Controlled annular motion of the aerodynamic flows in the part of the working space between the furnace wall and the electrodes increases convective heat transfer to the cold solid charge, forms a reliable and uniform slag crust on the water-cooled wall, and alleviates the deposition of process dust on the electrodes. A numerical study is performed using the SolidWorks Flow Simulation program and boundary conditions that reflect the actual operating conditions in the furnaces.Improving the gas dynamics in the working space of modern electric-arc steelmaking furnaces (EAFs) to provide for efficient heat transfer and rapid, uniform heating of the charge over the entire surface of the bath is a technically complex problem. Experience in the operation of EAFs shows that optimizing the arrangement of the fuel-combustion devices (FCDs) is an empirical undertaking. Any changes that need to be made to the locations of the FCDs have already been incorporated into the design of new prototypes, and the expediency of those changes are evaluated based on the results obtained from the furnaces' operation. The potential for putting new ideas to practical use on existing furnaces is always limited, and conducting experimental studies requires large amounts of time to prepare for and coordinate the necessary operations. In the investigation discussed in this article, the above problem was addressed through computer modeling and engineering analysis.We used a 3D model of the furnace (Fig. 1) that was previously constructed in the chart-and-graphics editor of the system KOMPAS-3D and then imported into the supplemental software of the program SolidWorks Flow Simulation to calculate the gas dynamics of the furnace's working space.Models differing in the locations of the FCDs were examined. In the first model, FCD location was chosen in accordance with a design developed by the company "Danieli" (variant A). In the second model, the FCDs were positioned in accordance with the recommendations made in [1] based on the results of a graphical analysis of the propagation of

Results of the design analysis carried out using computer software are presented for boundary data complying with the currently operating state-of-the-art arc steel furnace. Flow of natural gas combustion products and oxygen are reviewed for the radial and tangential burner arrangement in the working space between the wall and the electrodes. Location of high temperature fields is determined and the expected heat transfer to the charge materials through the active surface participating in heat exchange is evaluated. Precipitation degree is determined for the dust participating in scull generation on a wall water-cooled surface and significant reduction of dust effect on electrodes.

Аннотация. Представлены результаты анализа материального, элементного по кислороду и теплового балансов рабочего пространства современной дуговой сталеплавильной печи емкостью 120 т. Показано, что приход теплоты при окислении железа и других компонентов шихты настолько значителен, что тепловой режим и технологический процесс в целом приобретают признаки автогенного. Существенные потери с химическим недожогом свидетельствуют о неудовлетворительной организации аэродинамических потоков в объе ме рабочего пространства печи. С использованием компьютерной программы SolidWorks Flow simulation рассмотрены аэродинамические потоки и температурные поля в зоне нахождения холодной шихты, расположенной между электродами и внутренней поверхностью стены печи. Рекомендован рациональный способ установки газокислородных горелок, фурм подачи кислорода и эжекторов для ввода углеродсодержащих материалов в ванну печи.

The work deals with the particular combustion characteristics of methane family hydrocarbons (methane, ethane, propane, butane) and wet natural gas with process oxygen at carbon dioxide and water steam dissociation in a state-of-the-art arc steelmaking furnace. An algorithm is developed to calculate chemistry, the amount and concentration of combustion products at carbon dioxide and hydrogen dissociation, their physical and thermophysical parameters; heating power, balance and actual temperature, heat and pyrometric factors are evaluated considering heat transfer by radiation into unbounded medium. Based on the calculation results the recommendations are given for development of cold charge material heating conditions in order to minimize dusting, carbon oxide and hydrogen and charge material loss.

The temperature distribution in the working space of an electric-arc steelmaking furnace built by the company "Danieli" and equipped with radially positioned fuel-burning devices is analyzed. It is concluded that the temperature field is quite nonuniform, and the suggestion is made to reposition the gas-oxygen burners into a tangential configuration. Computer modeling is used to determine the temperature distribution in the furnace's working space for radially and tangentially arranged burners.