CHARACTERISTICS OF THREE-PHASE CURRENT ARCS, BURNING ON A HORIZONTAL SURFACE, WITH THEIR ELECTROMAGNETIC INTERACTION
Introduction. Multi-electrode arc furnaces using three-phase alternating current are widely used in metallurgy. The presence of several electric arcs creates a system with specific properties that are absent with a single burning arc. These properties are associated with the behavior of the magnetic field near three arcs, with the appearance of additional electromagnetic forces that change the shape and size of the arcs, and hence their thermal radiation. The intensity of electromagnetic interactions, the shape of the arc and its dynamic behavior, which in turn significantly affects the thermal work of the furnace, depend on the geometry of the arcs and the current strength. Knowing the nature of the forces acting on the arc, its position and behavior is important in the design and operation of furnaces, increasing the efficiency of management and automation of their work. The aim of the research is to study the behavior of the main characteristics of free electric arcs of a three-phase current burning on a horizontal surface, by creating the appropriate mathematical, algorithmic and software. Materials and methods. When performing the work, methods of computational mathematics and theory of algorithms were used. The created software using the Matlab application development tools and the MathCAD package was based on well-known methods: numerical integration and finding the minimum functions of many variables. Results. Issues related to the study of a system of three simultaneously burning arcs are considered. The analysis of the behavior of the magnetic field near three arcs is carried out. The electromagnetic forces that change the shape and size of arcs, and therefore their thermal radiation on a horizontal surface have been investigated. The simulation results were indirectly confirmed by experimental data conducted on an industrial furnace. Conclusion. Algorithms and programs have been created that allow to: evaluate the effect of electromagnetic fields on devices and humans located near arc furnaces; to study the behavior of the average integral electromagnetic forces acting on electric arcs; calculate and visualize the heat flux incident on a horizontal surface, depending on the geometry of the arcs and their parameters. Based on the created algorithms, special software can be created that is built into the system of automated regulation and prediction of the thermal operation of multi-electrode arc units to increase the reliability of evaluating the heat perception of a charge and water-cooled panels, wear of the furnace lining under different technological modes of arc burning.