HURIN O. Development and Research of a Control System with a Model of an Ammonia Synthesis Column in Ammonia Production

Dissertation for the degree of Doctor of Philosophy in the field of knowledge 15 Automation and Instrumentation 151 Automation and Computer-Integrated Technologies. – Volodymyr Dahl East Ukrainian National University of the Ministry of Education and Science of Ukraine, Kyiv, 2025. The dissertation is devoted to the creation of a computer-integrated control system with a mathematical model of the ammonia synthesis column, aimed at increasing the efficiency, stability, and energy efficiency of the ammonia production process. A comprehensive mathematical model of the ammonia synthesis column has been developed, which takes into account heat and mass transfer processes in the reaction zones, the influence of cold bypasses, and recuperative heat exchange. The model makes it possible to determine optimal temperature–concentration regimes along the height of the column and to evaluate the efficiency of technological equipment operation under different loads. An adaptive model-based control algorithm is proposed, which combines parametric identification of the mathematical model and an optimization search for column operating modes. This approach provides the ability to dynamically adjust parameters in real time, increases control accuracy, and reduces the influence of external disturbances. The structure of the computer-integrated control system for the ammonia synthesis column has been developed and implemented on the basis of the Siemens SIMATIC S7-400 programmable logic controller and the SCADA TRACE MODE 6 visualization system, which allows real-time monitoring and control of the technological process. The conducted simulation modeling has shown that the use of the model-based control system makes it possible to increase the ammonia concentration at the column outlet by approximately 1% compared to the regulatory characteristics, reduce the duration of transient processes, and ensure an aperiodic nature of parameter changes without exceeding permissible limits. The obtained research results have significant practical importance for the chemical industry, since the implementation of the model-based control system contributes to increased productivity, reduced energy consumption, stabilization of process parameters, and lower operating costs. In addition, the mathematical model and the proposed algorithms can be used as an educational and research tool for training automation engineers and developers of industrial control systems. The results obtained open up prospects for the further development of intelligent control systems for complex chemical-technological processes and the creation of digital twins of technological objects for optimizing industrial ammonia production.