БАГАТОРІВНЕВА ОПТИМІЗАЦІЯ ПАРАМЕТРІВ ТЕПЛОУТИЛІЗАЦІЙНОЇ СИСТЕМИ КОТЕЛЬНИХ УСТАНОВОК

• Дата: 2025
• Автори: Fialko, N., Stepanova, A., Shevchuk, S., Sbrodova, G., Martiuk, O.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Engineering Thermophysics of NAS of Ukraine 2025
• Онлайн доступ: https://ihe.nas.gov.ua/index.php/journal/article/view/625
• Назва журналу: Thermophysics and Thermal Power Engineering

The results of multi-level optimization of the operating and structural parameters of the heat recovery system of a heating boiler plant with a water-heating heat-recovery exchanger designed to heat return heat-network water are presented. The boiler plant is equipped with a heater of cooled flue gases by direct boiler water to prevent condensation in its gas exhaust channels. In the performance of optimization studies, the boiler operation mode was implemented, which corresponded to the condensation operation mode of the water-heating heat-recovery exchanger. The heat exchange surfaces of the heat-recovery exchanger and gas-heater were made up of finned tubes with a steel base and aluminum fins. The boiler return water and direct water temperatures corresponded to the heat-network schedule with a heat-transfer agent temperature difference of 25°C and a design air temperature of -20°C. The exhaust gases temperature after the boiler in nominal mode corresponded to 166 °C. A multi-level optimization methodology is proposed that allows reducing the general optimization problems of a heat recovery system to simpler, coordinated local optimization problems of each optimization level. The purpose of the work is to increase the exergy efficiency of a heat recovery system through multi-level optimization of operating, technological and structural parameters. To achieve this purpose, the following tasks were set: to develop a block diagram of multi-level optimization and a recursive level bypass scheme; to develop mathematical models for optimizing the parameters of each level; using a recursive optimization level bypass scheme to determine the optimal values ​​of the plant parameter. The basic principles of multi-level optimization of power plants are presented, according to which the heat recovery system is divided into five optimization levels. Statistical methods of experiment planning, exergy balance methods, matrix methods of exergy analysis, and variant and structural-variant methods of exergy analysis were used to build mathematical models. For each optimization level, methods for constructing mathematical models are selected, criteria for assessing exergy efficiency and varying parameters are proposed. The variable parameters of the given level object are used as variable parameters, and the optimal parameters, which are the results of solving local optimization problems of other levels, are used as constant parameters. The efficiency assessment criteria chosen were the Kirpichov energy criterion, heat and energy, energy and technology criteria, and specific material intensity. The functional dependencies and graphs of the efficiency criteria dependencies on the parameters of the heat recovery system elements are presented. The functional dependencies take into account change in exhaust gas humidity in the “wet” zone of the condensing heat recovery exchanger. At each optimization level, the corresponding optimization problems were solved and the operating and structural parameters optimal values of the condensing water-heating heat recovery exchanger and gas-heater were determined. Using a recursive bypass scheme of optimization levels, the optimal values parameters of the heat recovery system were determined, which allows increasing the coefficient the use heat of fuel of the plant by 5...8%.