Mechanism analyses of pressure effect on lean flammability limits of hydrogen/air flames

Bo Li, Yang Zhang, Hai Zhang, Chung K. Law

Research output: Contribution to conferencePaperpeer-review

Abstract

The lean flammability limits (LFL's) of H2/air mixtures were numerically determined over a wide range of pressures and under unburned temperature of 300 K. One-dimensional freely propagating flames were computed using PREMIX code. A one-point continuation method was used to solve around singular points as LFL is approached. Simulation results revealed that as pressure increases, LFL's of H2/Air mixtures increase first and then maintain nearly the same value until p = 40.5 atm. Kinetic effects of pressure on LFL's were assessed by path and sensitivity analyses, results revealed that as pressure increases, the importance of the dominative branching reaction at ambient pressure H + O2 = OH + O diminishes, while the HO 2-H2O2 kinetics controls the process of overall reaction. At the same time, the attendant limit flame temperature first increases and then decreases with increasing pressure, and this non-monotonic behavior can be explained as that the synergistic effect of chemical kinetics and radiation heat loss.

Original languageEnglish (US)
StatePublished - 2013
Externally publishedYes
Event9th Asia-Pacific Conference on Combustion, ASPACC 2013 - Gyeongju, Korea, Republic of
Duration: May 19 2013May 22 2013

Other

Other9th Asia-Pacific Conference on Combustion, ASPACC 2013
Country/TerritoryKorea, Republic of
CityGyeongju
Period5/19/135/22/13

All Science Journal Classification (ASJC) codes

  • Environmental Engineering

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