Cyclone Fired Boilers

As part of the full scale testing of Fuel Lean Gas Reburn (FLGRTM), Steag Energy Services (formerly ESA) modeled the Commonwealth Edison Joliet Station 9 cyclone fired boiler. Joliet is fired from nine cyclones in a 4 opposed to 5 configuration, and generates 320 MW. Steag Energy Services (formerly ESA) modeling of the baseline configuration revealed the existence of a large recirculation zone established by the non-symmetry of the 5 cyclone wall. This prediction was so unusual and striking that additional furnace velocity testing was conducted; the testing confirmed the predictions of the model. With a thorough understanding of the baseline, Steag Energy Services (formerly ESA) employed the modeling to choose positions for gas injection nozzles to produce high NOx reductions and low CO emissions. A 47 % reduction in NOx was predicted for 7 % natural gas injection.

Initial testing showed a maximum NOx reduction of 43 %. Subsequently, as a quality check, separate models were conducted by both Babcock & Wilcox and NGB Technologies, after initial testing was conducted. Both models confirmed the functioning of the design chosen by Steag Energy Services (formerly ESA). Long term testing of the FLGRTM system showed an average 38 % NOx reduction using 6.5% natural gas, further confirming the design predicted by the CFD model.