Using vortex burner devices to reduce emissions of harmful substances in thermal power engineering

A study examined the effect of a swirling pulverized-coal flow on heat and mass transfer in the furnace of the BKZ-75 boiler at the Shakhtinsk thermal power plant (Kazakhstan), operating on high-ash coal (ash content >35 %). Two air–fuel supply configurations were considered: a conventional straight-through scheme with burners on opposite walls and a modified swirling scheme with burners inclined at 30° toward the boiler's center. The novelty of the work lies in the first application of an integrated systems-based approach that combines theory, digital modeling (digital twins), computational experiments, IT tools, and 3D visualization, validated against both experimental and theoretical data. This approach enabled a detailed evaluation of the impact of swirl on heat and mass transfer, as well as environmental performance, during high-ash coal combustion in a real industrial boiler. The results show that swirl significantly redistributes velocity, temperature, and species concentration fields in the furnace. It expands the high-temperature zone, increases flame core temperature, and lowers the outlet temperature, improving thermal performance and reducing local thermal loads. For the BKZ-75 boiler, pollutant emissions are reduced compared with the straight-through scheme: CO by ∼15 %, SO2 by 7 %, and NO2 by 20 %. The study confirms that optimizing flame aerodynamics through the use of pulverized-coal swirl enhances combustion efficiency and reduces environmental impact when using low-quality, high-ash coals at operating thermal power plants.