Oxides of nitrogen emissions from turbulent jet flames: Part II-Fuel dilution and partial premixing effects

Journal Article · Sat May 01 04:00:00 EDT 1993 · Combustion and Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(93)90107-E· OSTI ID:6441931

Turns, S R; Myhr, F H; Bandaru, R V; Maund, E R ^[1]

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1. Pennsylvania State Univ., University Park (United States)

Measurement of NO[sub x] emission indices, flame radiant fractions, and visible flame length were made for turbulent, nonpremixed, jet flames for which various amounts of inert diluent or air were mixed with the fuel. The objective of the study was to explore further the role of flame radiation in NO[sub x] production in jet flames. Four fuels, CH[sub 4], C[sub 2]H[sub 4], C[sub 3]H[sub 8], and a 95% CO/5% H[sub 2] mixture (by mass); three inert diluents, N[sub 2], Ar, and CO[sub 2]; and air premixing were employed in parametric tests. Complementary dilution experiments were run with laminar jet flames using the three hydrocarbon fuels and N[sub 2]. For the turbulent flames, the results showed that the effects of dilution and premixing were strongly dependent on fuel type. Flame temperatures and NO[sub x] emissions increased when the more sooting fuels (C[sub 3]H[sub 8] and C[sub 2]H[sub 4]) were diluted or partially premixed, resulting in increased NO[sub x] emissions. The opposite trend was observed for the nonluminous CO/H[sub 2] flames. Using the results reported here and from Part I. of this study, the effects of residence time, flame temperature, and departure from equilibrium on NO[sub x] emissions, regardless of what parameter affected the change, were well characterized by regressing characteristic NO[sub x] production rates as a function of nonadiabatic characteristic flame temperatures and global residence times. Separate regressions for the hydrocarbon and CO/H[sub 2] flames showed a weaker dependence of NO[sub x] on temperature for the hydrocarbons, suggesting that the prompt NO mechanism is quite active in these flames.

• OSTI ID: 6441931
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 93:3; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000 -- Petroleum-- Combustion
03 NATURAL GAS
034000 -- Natural Gas-- Combustion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKANES
ALKENES
ARGON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
DILUTION
ELEMENTS
EMISSION
EQUILIBRIUM
ETHYLENE
FLAMES
FLUID FLOW
FLUIDS
GASES
HYDROCARBONS
HYDROGEN
KINETICS
LAMINAR FLOW
METHANE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
PROPANE
RARE GASES
REACTION KINETICS
SYNTHESIS GAS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TURBULENT FLOW