CHEMICAL-STRUCTURE OF LAMINAR PREMIXED NATURAL-GAS FLAMES - INFLUENCEOF EQUIVALENCE RATIO

Three premixed natural gas flames (Phi = 0.5; 1.0; 1.3) were analyzed at low-pressure (0.105 atm.). Mole fraction profiles of stable and rea ctive species and temperature were measured using molecular beam/mass spectrometry, gas chromatography and thermocouple techniques. Experime ntal data were compared with predictions from a one-dimensional model using a detailed chemical mechanism (Tan et al., 1994 [5]). For the de tected species a generally good agreement was obtained in shape and lo cation, except in magnitude in the case of C2H6, C4H10, C5H12, C6H14 r eactants and of C2 and C3 intermediates. The most noteworthy result of our experiments is that the C4, C5 and C6 hydrocarbons chemistry stro ngly affects the intermediate species and has to be taken into account in the model. Various aspects of the flames chemistry are discussed.