Stabilized three-stage oxidation of DME/air mixture in a micro flow reactor with a controlled temperature profile
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)
Ignition and combustion characteristics of a stoichiometric dimethyl ether (DME)/air mixture in a micro flow reactor with a controlled temperature profile which was smoothly ramped from room temperature to ignition temperature were investigated. Special attention was paid to the multi-stage oxidation in low temperature condition. Normal stable flames in a mixture flow in the high velocity region, and non-stationary pulsating flames and/or repetitive extinction and ignition (FREI) in the medium velocity region were experimentally confirmed as expected from our previous study on a methane/air mixture. In addition, stable double weak flames were observed in the low velocity region for the present DME/air mixture case. It is the first observation of stable double flames by the present methodology. Gas sampling was conducted to obtain major species distributions in the flow reactor. The results indicated that existence of low-temperature oxidation was conjectured by the production of CH{sub 2}O occured in the upstream side of the experimental first luminous flame, while no chemiluminescence from it was seen. One-dimensional computation with detailed chemistry and transport was conducted. At low mixture velocities, three-stage oxidation was confirmed from profiles of the heat release rate and major chemical species, which was broadly in agreement with the experimental results. Since the present micro flow reactor with a controlled temperature profile successfully presented the multi-stage oxidations as spatially separated flames, it is shown that this flow reactor can be utilized as a methodology to separate sets of reactions, even for other practical fuels, at different temperature. (author)
- OSTI ID:
- 21331459
- Journal Information:
- Combustion and Flame, Vol. 157, Issue 8; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
METHYL ETHER
COMBUSTION
FORMALDEHYDE
AIR
MIXTURES
TEMPERATURE RANGE 0400-1000 K
FLAMES
CHEMILUMINESCENCE
VELOCITY
TEMPERATURE RANGE 0273-0400 K
IGNITION
HEAT
CALCULATION METHODS
ONE-DIMENSIONAL CALCULATIONS
DISTRIBUTION
SAMPLING
STOICHIOMETRY
FLAME EXTINCTION
COMBUSTION PROPERTIES
TEMPERATURE RANGE 1000-4000 K
Microflow reactors
Three-stage oxidation
Low-temperature oxidation
Cool flames
Mesoscale combustion
Microcombustion
Dimethyl ether