Identification of the initial particle size distribution for coal combustion simulations

Abstract

AbstractPulverized coal generally features wide particle‐size distributions (PSD). How to set an initial PSD in coal combustion simulation remains an open question. To answer this, the Gaussian‐quadrature theory was applied to provide a discrete reconstruction of the PSD described by Rosin‐Rammler and Upper‐Limit functions. From the perspective of the moments of PSD, a theoretical analysis was conducted for mass, momentum, and energy exchange terms between gas and particle phases in pulverized coal jet flame. The analysis presented that the first, the second and the third moments of PSD were the most important to capture the flame ignition behavior. The large eddy simulations showed that the proposed method with two or more particle sizes could provide good predictions of flame ignition distances. And Sauter mean diameter (D32) could represent the complete PSD when predicting the ignition behavior of pulverized coal jet flame.