NO{sub x} emission and major species concentrations in partially premixed laminar methane/air co-flow jet flames

Journal Article · Wed May 01 04:00:00 EDT 1996 · Combustion and Flame

DOI:https://doi.org/10.1016/0010-2180(95)00177-8· OSTI ID:251080

Gore, J P; Zhan, N J ^[1]

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1. Purdue Univ., West Lafayette, IN (United States)

Measurements of visible flame heights, global radiative heat loss fractions, distributions of mole fractions of stable gas species, and pollutant emission indices in laminar partially premixed flames burning various fuel-rich mixtures of CH{sub 4} and air in an overventilating co-flow of air are reported. Mole fractions of CO{sub 2}, CO, H{sub 2}, O{sub 2}, N{sub 2} CH{sub 4}, C{sub 2}H{sub 4} and C{sub 2}H{sub 2} were measured, using sampling and gas chromatography, at several radial locations at three different heights above the fuel tube for a fixed fuel flow rate and six different fuel tube equivalence ratios. Mole fractions of H{sub 2}O were inferred from the dry based measurements. With increasing levels of partial premixing following effects are observed: (1) the visible flame height decreases and the overall flame color changes from yellow to blue; (2) the radiative heat loss fraction first decreases and then reaches a constant value; (3) the mole fractions of CO decrease and those of CO{sub 2} and H{sub 2}O increase in the lean parts of the flame; (4) mole fractions of C{sub 2}H{sub 2} decrease and those of C{sub 2}H{sub 4} first increase and then decrease in the rick parts of the flame; (5) mole fractions of CO and H{sub 2} first decrease slightly and then increase in the rich parts of the flame; and (6) the O{sub 2} mole fractions at the point of negligible CH{sub 4} mole fraction decrease. Measurements of emission indices for NO, NO{sub x}, CO and HC show that, for a fixed fuel flow rate and overall equivalence ratio, an optimum level of partial premixing exists.

• OSTI ID: 251080
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 3 Vol. 105; ISSN 0010-2180; ISSN CBFMAO
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ACETYLENE
CARBON DIOXIDE
CARBON MONOXIDE
CHEMICAL REACTION YIELD
COMBUSTION KINETICS
ETHYLENE
FLAMES
GAS ANALYSIS
HYDROGEN
LAMINAR FLOW
METHANE
MORPHOLOGY
NITRIC OXIDE
NITROGEN
NITROGEN OXIDES
OXYGEN
RADIANT HEAT TRANSFER
WATER VAPOR