Numerical simulation of 3-D turbulent gas-particle flows in a nonslagging cyclone combustor

Abstract

The 3-D turbulent gas-particle flows in an innovative combustor called “Spouting-Cyclone Combustor” are simulated using a k-ɛ-Ap two-phase turbulence model. The results show that: (1) The predicted results in the spouting zone are in good agreement with the experimental ones; the predicted gas flow field in the cyclone zone is near to that measured; (2) In the spouting zone, there is a large-size gas-particle recirculation zone and a small-size one in the x-r plane, which is favorable to burning coarse coal particles; In almost every r-θ plane, there are several gas-particle vortices, which is beneficial to the mixing, heat and mass transfer between two phases, thus, to the two-phase combustion. (3) There is remarkable velocity slip between gas and particle phases; (4) In the cyclone zone, predictions show the occurrence of recirculating secondary flows and counter swirling flows in some cross sections, such phenomena are difficult to be observed by experimental methods.