Numerical Modeling of Fractional Combustion of Pulverized Coal Fuel
DOI:
https://doi.org/10.24160/1993-6982-2024-4-108-115Keywords:
CFD, particle size, fractional combustion, unburned carbon, NOх emissionAbstract
When combusting polyfractional coal dust, the flame contains particles whose sizes differ by one or two orders of magnitude. Since at the beginning of the flame small fuel particles burn faster and consume a significant part of the oxygen, large fuel particles, which determine incomplete combustion, burn in an oxygen-depleted atmosphere. This drawback can be eliminated using the technology of fractional combustion of pulverized coal fuel, which consists of dividing polyfractional coal dust into fractions of different sizes and then burning them under different conditions. The purpose of this study is to assess the efficiency of fractional combustion of pulverized coal fuel by comparing the results of numerical modeling of the combustion of polyfractional and fractionated coal dust. A comparative analysis has established that the separation of polyfractional coal dust into «coarse» and «fine» fractions, followed by their introduction into the furnace at different heights leads to a decrease unburned carbon by 1.13÷1.68% and a simultaneous decrease in the NOx concentration at the outlet furnace by 7.3÷13.9%. Moreover, the greater the distance between the tiers of burners, the more significant the effect. The limiting factor when choosing where to introduce the «fine» fraction of pulverized coal fuel into the furnace is the temperature of the flue gases at the outlet of the furnace. Thus, fractional combustion of pulverized coal fuel can be effectively used to reduce unburned carbon and slightly reduce NOx emissions. The obtained results can be used to develop new designs of pulverized coal furnaces.
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Для цитирования: Пронин А.К., Заворин А.С. Численное моделирование пофракционного сжигания пылеугольного топлива // Вестник МЭИ. 2024. № 4. С. 108—115. DOI: 10.24160/1993-6982-2024-4-108-115
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Исследование выполнено при поддержке Госзадания № FEWZ-2024-0013 «Научно-технические основы и прикладные решения ресурсоэффективной термической переработки органического сырья с получением продуктов с высокой добавленной стоимостью для энергетической, металлургической и сельскохозяйственной отраслей»
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Конфликт интересов: авторы заявляют об отсутствии конфликта интересов
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For citation: Pronin A.K., Zavorin A.S. Numerical Modeling of Fractional Combustion of Pulverized Coal Fuel. Bulletin of MPEI. 2024;4:108—115. (in Russian). DOI: 10.24160/1993-6982-2024-4-108-115
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The study was carried out with the support State Task No. FEWZ-2024-0013 «Scientific and Technical Foundations and Applied Solutions for Resource-efficient Thermal Processing of Organic Raw Materials to Produce Products with High Added Value for The Energy, Metallurgical and Agricultural Industries»
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Conflict of interests: the authors declare no conflict of interest
