Numerical simulation of dynamic characteristics of bituminite-fired boiler after mixing lignite for combustion

Abstract

Abstract If the lignite is mixed for combustion in the bituminous-fired boilers in a power plant, less primary air volume is required to avoid burner nozzle coking due to the high volatility of lignite. Stimulate the boiler’s dynamic field under the design conditions after reducing primary air rate using the Fluent software, and analyze the diameter of the tangent circle in the furnace and the process of primary air’s stiffness attenuation. The result shows that as the primary wind rate and speed decrease, the dynamic field in the furnace changes greatly, while the speed of the adherent wind increases, and the wall brushing phenomenon occurs. In order to ensure a dynamic field in the furnace, it is necessary to place a central cross partition to increase the rigidity of the primary air, and to prevent the primary air from decaying too quickly or deflecting towards the wall. The result can be used as a reference for the design and modification of the same type of boiler burner.