| OCR Text |
Show temperature (> 5000 degF) . Even for a fixed fuel, oxidizer and stoichiometry, actual flame temperatures vary widely depending upon burner design . A well-accepted method for NOx reduction is to lower the actual flame temperature using techniques like flue gas recirculation or water injection into the flame . r 4000r---------------------__________ __ >' E Co 3000 .:: 2000 o Z 1000 O~----~~~----~----~--~----~ 2000 3000 4000 5000 TEMPERATURE (degF) Fig. 9 Equilibrium NO predictions as a function of flame temperature for CH4 combusted stoichiometrically with an oxidizer consisting of 95 % 02 and 5% N2. CONCLUSIONS Adiabatic equilibrium predictions and experimental measurements showed that NO decreased as the oxygen concentration in the oxidizer increased from 80 to 100 % while it increased with stoichiometry from 1.8 to 2.5. Although the adiabatic equilibrium predictions were about an order of magnitude higher than the experimental data, the trends were virtually the same. This simplitied modeling can therefore be very useful in the qualitative analysis and design of new combustion systems. REFERENCES 1. KezerIe, 1., private communication, Chicago, IL, 1992. 2. Gordon, S. and B.l. McBride, "Computer Program for Calculation of Complex Chemical Equilibrium Compositions, Rocket Performance, Incident and Reflected Shocks, and Chapman-louguet Detonations ," NASA report SP-273, 1971. 3. Baukal, C.E. and A.I. Dalton, "Nitric Oxide Measurement's in Oxygen-Enriched AirNatural Gas Combustion Systems," Proceedings of (he 2nd Fossil Fue/ C0l17bustion Symposillln , American Society of r-.1echanical Engineers PO-Vol. 30, pp. 75-79, 1990. 8 |
