Abstract
The flow field characteristics of confined flames have been investigated for propane nonpremixed flames in cylindrical furnaces. The effects of furnace inner diameter D1, air inlet velocity difference ΔUa, and global equivalence ratio φ on the flow field are related to NOx emission. The emission index of NOx, EINOx, decreases roughly with the increases of the above parameters. This decrease is observed as a consequence of flame stretch and dilution by the burned gas. The flame stretch is related to the velocity difference introduced by multiple inlets, and the dilution is attributable to the recirculation structure formed at the bottom of the furnace. The present investigation shows the mechanism of burner/chamber configuration inciting the flow field and indirectly controlling NOx emission.
