(261c) Studies On Coal Jet Ignition Under Oxy-Fuel Combustion Conditions

The objective of the research described here is to understand and predict the effects on ignition characteristics of the near burner zone during oxy-coal combustion processes, with a view also to providing data for subsequent simulation validation studies. This paper presents results of research directed at controlling flame aerodynamics by adjusting the partial pressure of oxygen, PO2, in the transporting fluid, and through other techniques, to enhance coal ignition, and thereby promote flame attachment/detachment and reduce pollutant formation. A novel, down-fired laboratory furnace was designed and validated. This facility consists of a 100 kW furnace and axial burner, with arrays of electrically-heated panels in the burner zone to allow variations in near-burner heat loss. The furnace also has visual access of the near burner flame zone through a quartz window, and allows for stabilization of Type 0 axial turbulent diffusion flames with control of jet velocities and momenta. Preliminary data show how flame attachment increased with PO2 and presence of coal fines. These variables were also shown to have a first-order influence on NOx. Future work will use these data to validate simulations of axial coal jet ignition.

Keywords: Oxy-fuel combustion, pulverized coal, PO2, flame attachment