OH-LIF measurement of H2/O2/N2 flames in a micro flow reactor with a controlled temperature profile

14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications

物理学;能源学

Shimizu, T.^1 ; Nakamura, H.^1 ; Tezuka, T.^1 ; Hasegawa, S.^1 ; Maruta, K.^1,2

Institute of Fluid Science, Tohoku University, 2-1-1, Aoba-ku, Miyagi, Sendai

980-8577, Japan^1

Far Eastern Federal University, 8 Suhanova St., Vladivostokok

690950, Russia^2

关键词: Controlled temperature;    Equivalence ratios;    Flames with repetitive extinction and ignitions (FREI);    Ignition characteristics;    Intermediate flow;    Micro-flow reactor;    Rate of production analysis;    Rich conditions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/557/1/012075/pdf
DOI  :  10.1088/1742-6596/557/1/012075

来源: IOP

【 摘 要 】

This paper presents combustion and ignition characteristic of H2/O2/N2flames in a micro flow reactor with a controlled temperature profile. OH-LIF measurement was conducted to capture flame images. Flame responses were investigated for variable inlet flow velocity, U, and equivalence ratio, φ. Three kinds of flame responses were experimentally observed for the inlet flow velocities: stable flat flames (normal flames) in the high inlet flow velocity regime; unstable flames called Flames with Repetitive Extinction and Ignition (FREI) in the intermediate flow velocity regime; and stable weak flames in the low flow velocity regime, at φ 0.6, 1.0 and 1.2. On the other hand, weak flame was not observed at φ 3.0 by OH-LIF measurement. Computational OH mole fractions showed lower level at the rich conditions than those at stoichiometric and lean conditions. To examine this response of OH signal to equivalence ratio, rate of production analysis was conducted and four kinds of major contributed reaction for OH production: R3(O + H2 H + OH); R38(H + O2O + OH); R46(H + HO2 2OH); and R86(2OHO + H2O), were found. Three reactions among them, R3, R38 and R46, did not showed significant difference in rate of OH production for different equivalence ratios. On the other hand, rate of OH production from R86 at φ = 3.0 was extremely lower than those at φ 0.6 and 1.0. Therefore, R86 was considered to be a key reaction for the reduction of the OH production at φ = 3.0.