Simulation of 3-D gas-particle flows and coal combustion in a tangentially fired furnace using a two-fluid-trajectory model

A two-fluid-trajectory (TFT) model is used to simulate three-dimensional (3-D) gas-particle flows and coal combustion in a tangentially fired furnace. A grid system, rotated by an angle, is proposed to reduce the numerical diffusion caused by non-orthogonal crossing of the burner jets with the grid lines. The predictions of cold two-phase flows using the two-fluid (TF) model are compared with those using the stochastic trajectory model (ST model of particle phase) and the phase Doppler particle anemometer (PDPA) measurements. The predicted particle concentration distribution using the TF model is in agreement with PDPA measurements, while the ST model gives too high particle concentration in the near-wall region, not observed in experiments. The 3-D coal combustion predictions give the hot-flow field, coal concentration, gas temperature, species concentration, and heat fluxes on the walls. The prediction results for coal combustion show a local high-temperature zone near the exit of the furnace.