Aerodynamic processes and heat exchange in the furnace of a steam boiler with a secondary emitter

Abstract The use of water-tube boilers is common in industrial and municipal boiler houses and they are used as the sources of heat and steam supply. The introduction of measures that ensure environmental performance at an acceptable level, the use of modern burner devices and automation of boilers for worn-out and obsolete boiler designs require a significant amount of reconstruction and significant financial costs. The solution of the problems of burner device modernization, analysis and selection of optimal operating conditions for furnaces and boilers requires the application of modern methods of mathematical modeling. Modern technologies for reducing nitrogen oxides should improve the ecological safety of boilers and increase the efficiency of their operation. The results of a numerical study of heat exchange processes when burning the fossil fuels have shown the efficiency of placing a secondary tubular reversible emitter in the volume of a boiler furnace. It is found that the density of the radiant heat flux increases by 15–20%, the temperature of the flue gases at the outlet from the furnace decreases and amounts to 970 °C. The dimensions of the flame torch exclude its collision with the surfaces of screen tubes. During the combustion of the gas-air mixture, the concentration of nitrogen oxides at the outlet from the boiler furnace does not exceed 125 mg/m 3 .