Predicting the near-burner-zone flow field and chemistry of swirl-stabilized low-NO_x flames of pulverized coal using the rng-k-epsilon, RSM and k-epsilon turbulence models

摘要

While recently substantial progress has been achieved in predicting properties of high NO_x (type 2) flames, the task of computing low-NO_x flames (type 1) happens to be much more complex. This is due to difficulties in predicting the complex near-burner-zone flow field of type 1 flames which can be characterized by a nonswirling fuel jet penetrating either partially or fully through the swirl-induced reverse flow zone. The objective of this paper is to examine what imporvements to the predicted near-burner-zone flow field, chemistry, and subsequent NO_x emissions can be made by applying the Reynolds stress (transport) model and the renormmalization group theory k-epsilon model rather than the standard k-epsilon model. To this end, the 2-MW_t flame data collected at the IFRF have been utilized.