CONSTRUCTION OF A MATHEMATICAL MODEL OF THE THERMAL AND TECHNOLOGICAL PROCESSES THAT OCCUR DURING THE REFINING PERIOD IN OPEN-HEARTH FURNACES

摘要

At a number of ferrous metallurgy plants in Russia, the main pieces of equipment used n the steelmaking conversion are open-hearth (OH) furnaces. Economic and technical obstacles preclude the replacement of these units by more modern and more productive furnaces. Thus, the problem of obtaining a semifinished product with the desired characteristics within a certain time interval while minimizing production costs and pollution is still a key issue. In addition to certain organizational changes, solving the problem will require a further improvement in the methods used to control the complex technological and heat-engineering system used in the steelmaking operation-the open-hearth furnace. Such improvement can be realized by using modern control algorithms based on a mathematical description of the processes in question.Most of the existing mathematical models of the processes that take place in hearth furnaces were developed during the 1960s and 1970s. The scientific and practical value of the results was diminished by the then relatively meager knowledge of the OH process, the fact that the furnace was regarded as a closed equilibrium system and that certain reactions and phenomena were examined on the basis of formal kinetics, the coordinates of the state vectors, and control mechanisms grounded in statistical analysis, and the unreliability and slowness of the computers that were then available.