Effect of Parameters of DirectFlow Burner on Combustion Characteristics of OxyCoal

Abstract:

The software FLUENT was applied on a Φ200 mm×2 m furnace to study the influence of jet momentum ratio and jet spacing on the flow field and combustion characteristics at O2/CO2 atmosphere. The results show that when the jet momentum ratio varies from 28 to 66, the peak of flue gas inner recirculation rate increases and then decreases, and the overall level of inner recirculation rate in the mixing zone is the largest when the jet momentum ratio is 48. When the jet spacing gradually increases, the recirculation zone on xz plane shifts downstream. Besides, the region where the concentration of oxygen volume is higher than 10% narrows, the temperature peak decreases slightly. However, the jet spacing must maintain a proper value. When the jet spacing is 75 mm, the recirculation zone on the xz plane narrows significantly, and the oxygen concentration in the reaction zone rises again, and, as a result, the temperature peak increases. The temperature peak is the highest (about 2 200 K) under coaxial jet condition, the max temperature increase is lower than the ignition temperature(790 K) only when the jet spacing is 60mm, indicating that the oxyMILD combustion state can be established.