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Flammability limits, ignition energy, and flame speeds in H₂–CH₄–NH₃–N₂O–O₂–N₂ mixtures

Pfahl, U. J. and Ross, M. C. and Shepherd, J. E. and Pasamehmetoglu, K. O. and Unal, C. (2000) Flammability limits, ignition energy, and flame speeds in H₂–CH₄–NH₃–N₂O–O₂–N₂ mixtures. Combustion and Flame, 123 (1-2). pp. 140-158. ISSN 0010-2180. doi:10.1016/s0010-2180(00)00152-8.

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Experiments on flammability limits, ignition energies, and flame speeds were carried out in a 11.25- and a 400-liter combustion vessel at initial pressures and temperatures of 100 kPa and 295 K, respectively. Flammability maps of hydrogen–nitrous oxide–nitrogen, methane–nitrous oxide–nitrogen, ammonia–nitrous oxide–nitrogen, and ammonia–nitrous oxide–air, as well as lean flammability limits of various hydrogen–methane–ammonia–nitrous oxide–oxygen–nitrogen mixtures were determined. Ignition energy bounds of methane–nitrous oxide, ammonia–nitrous oxide, and ammonia–nitrous oxide–nitrogen mixtures have been determined and the influence of small amounts of oxygen on the flammability of methane–nitrous oxide–nitrogen mixtures has been investigated. Flame speeds have been measured and laminar burning velocities have been determined for ammonia–air–nitrous oxide and various hydrogen–methane–ammonia–nitrous oxide–oxygen–nitrogen mixtures. Lower and upper flammability limits (mixing fan on, turbulent conditions) for ignition energies of 8 J are: H₂–N₂O: 4.5 ∼ 5.0% H₂(LFL), 76 ∼ 80% H₂(UFL); CH₄–N₂O: 2.5 ∼ 3.0% CH₄(LFL), 43 ∼ 50% CH₄(UFL); NH₃–N₂O: 5.0 ∼ 5.2% NH₃(LFL), 67.5 ∼ 68% NH₃(UFL). Inerting concentrations are: H₂–N₂O–N₂: 76% N₂; CH₄–N₂O–N₂: 70.5% N₂; NH₃–N₂O–N₂: 61% N₂; NH₃–N₂O–air: 85% air. Flammability limits of methane–nitrous oxide–nitrogen mixtures show no pronounced dependence on small amounts of oxygen (<5%). Generally speaking, flammable gases with large initial amounts of nitrous oxide or ammonia show a strong dependence of flammability limits on ignition energy.

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Shepherd, J. E.0000-0003-3181-9310
Additional Information:© 2000 The Combustion Institute. Published by Elsevier Inc. Received 1 February 1999, Revised 29 March 2000, Accepted 6 April 2000, Available online 14 September 2000. This work was supported by the U.S. Department of Energy under contract 929Q0015-3A, DOE W-7405-ENG-36. We thank Jerry Johnson for the support.
Funding AgencyGrant Number
Department of Energy (DOE)929Q0015-3A
Department of Energy (DOE)W-7405-ENG-36
Issue or Number:1-2
Record Number:CaltechAUTHORS:20200826-070747865
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Official Citation:U.J Pfahl, M.C Ross, J.E Shepherd, K.O Pasamehmetoglu, C Unal, Flammability limits, ignition energy, and flame speeds in H2–CH4–NH3–N2O–O2–N2 mixtures, Combustion and Flame, Volume 123, Issues 1–2, 2000, Pages 140-158, ISSN 0010-2180,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105109
Deposited By: Tony Diaz
Deposited On:26 Aug 2020 16:44
Last Modified:16 Nov 2021 18:39

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