Physical modeling of the M-shaped boiler furnace aerodynamics

Abstract

In order to increase the thermodynamic efficiency of the Rankine cycle, in Russia, China, the USA, and EU countries, new-generation power units with advanced ultra-supercritical (A-USC) steam parameters are being developed. Using A-USC steam parameters (temperature – 700-760 °C, pressure – 35 MPa) will lead to the need to use expensive nickel steels. A single-shell design of the M-shaped boiler for burning Kuznetsk coal grade TP with solid slag removal (SSR) was proposed to reduce the total length of the main steam pipelines. A solid fuel combustion scheme with direct-flow burners, nozzles and system of vertical-horizontal tangential flames (VHTF) has been developed for this boiler, which will ensure: emissions of nitrogen oxides into the atmosphere at a level lower than standard; continuous operation of the boiler in the absence of slagging of the furnace walls and overheating of the pipe metal; a high degree of burnout of coal dust, with the provision of the standard value of the mechanical underburning of fuel; long minimum boiler load at a level not exceeding 40% of the nominal one according to the conditions of coal dust combustion stability.