Behavior and effect on NOx formation of OH radical in methane-air diffusion flame with steam addition

A Numerical Study on the Effects of CO2/N2/Ar Addition to Air on Liftoff of a Laminar CH4/Air Diffusion Flame

“…The effects of adding various components of exhaust gas on the formation of pollutants have also been investigated by some researchers (Bundy et al, 2003;Guo and Smallwood, 2008;Li and Williams, 1999;Liu et al, 2001;Lock et al, 2007;Park et al, 2004;Zhao et al, 2002). Generally an additive to the oxidant or fuel stream of a diffusion flame causes variations in flame liftoff and other properties due to the change in combustion intensity.…”

Effect of steam addition on flame structure and NO formation in H2–O2–N2 diffusion flame

“…Furthermore a modified idea, which adds the high-temperature steam generated from the flue-gas heat-recovery boiler to combustor, may achieve high thermal efficiency and low pollutant emissions (Zhao et al, 2002). It should be, however, noted that the impact of added steam or water in these combustion systems has both sides.…”

“…One is, that is, that flame temperature usually has a tendency to decrease with the addition of diluents due to the limitation of reactive species and the heat capacity of added diluents (Li and Williams, 1999). The other is that chemical effects of added steam may enhance the burning itself Park et al, 2002;Zhao et al, 2002), leading abundant chain carrier radicals. In result these mutually contradictory effects should affect flame structure and NO emission significantly according to the quantity of added steam.…”

“…Cautious observation of recent researches in steam-added flames Park et al, 2002;Zhao et al, 2002) has made one find that the concentrations of H and O decrease and that of OH increases with increasing the quantity of added steam. Thus the flame strength, which results from the behaviour of the principal chain branching reaction, H+O 2 !…”

Recommendations on the prediction of thermal hazard distances from large liquefied natural gas pool fires on water for solid flame models.

“…Water vapor is also most likely entrained on the fuel side due to vigorous boiling at the LNG/water interface. Water addition has been used to control combustion systems such as internal combustion engine performance (Dryer 1977), gas turbine systems (Zhao 2002), and steam-assisted flares (Castineira 2006), with several studies demonstrating thermal/physical and chemical effects of water addition on flames. A few pertinent studies are detailed in the following.…”