Zhuchenko O. Mathematical modeling and optimal control of energy-intensive technological processes of carbon graphite production

The dissertation thesis contains the solution of the actual scientific and applied problem of the efficiency increase of the carbon-graphite production by means of developing computer systems of optimal control of the main energy-intensive technological processes of carbon-graphite production, which would meet modern requirements of resource and energy conservation. The production of graphitized items is complex, multi-stage and very energy-intensive. The system analysis of the technological complex of carbon-graphite production as a complex dynamic system was carried out. As a result of the analysis of all the technological complex components, technological processes are determined, the total energy consumption of which actually determines the energy consumption of the entire production. These technological processes include: calcination of carbonaceous materials in a mine-type furnace, formation of carbon products, their firing and graphitizing. It was executed a thorough study of temperature fields distribution of the technological processes under consideration at different operational stages. The results of this study demonstrated a significant temperature distribution in the working space of the technological apparatus, allowed to identify the zones with minimum and maximum temperatures, with a maximum temperature difference and the factors that influence the thermal conditions of the technological processes as well, which enables to consider these factors when developing control systems of technological processes. It is shown that the mathematical models of processes of calcining, forming, firing and graphitizing of carbon products, which for the thermal modes study of the corresponding technological processes of carbon-graphite production, require a considerable calculation time and, therefore, they cannot be used in their control systems in real time. The necessity of data simplification of the mathematical models is substantiated. It is introduced the concept of "operational" mathematical model of the technological process, being a simplified model that does not require long-term calculation and can be used in control systems of technological processes of carbon-graphite production. Based on the Fourier method, a method for simplifying mathematical models of objects with distributed parameters is developed, which includes the calculation of basis vectors and the model parametric identification. The algorithm for the basis-vectors calculation is proposed.