Heat release mechanisms in inhibited laminar counterflow flames

Journal Article · Mon Jan 01 00:00:00 EST 1996 · Combustion and Flame

DOI:https://doi.org/10.1016/0010-2180(95)00105-0· OSTI ID:215689

Lee, K Y; Cha, D J; Puri, I K ^[1]; Hamins, A ^[2]

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1. Univ. of Illinois, Chicago, IL (United States). Dept. of Mechanical Engineering
2. National Inst. of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Lab.

Investigations involving chemical inhibitors have to content with three interacting phenomena: (1) the cooling action due to the specific heat of the species; (2) the heat release due to their burning; and (3) inhibition associated with scavenging of critical radical species. This study investigated the effect of chloromethane on the heat release in methane-air nonpremixed flames. For comparison, the effect on the heat release due to the purely thermal action of nitrogen was also investigated. The flames were experimentally and numerically studied in a counterflow configuration, and the heat release was calculated from simulations involving detailed chemistry. When inert suppressants were added to the oxidizer stream of a nonpremixed flame, the global heat release decreased. Chloromethane addition to the fuel stream, however, increased the heat release. Whereas addition of nitrogen narrowed the heat release region, chloromethane addition to the oxidizer altered the flame stoichiometry, such that the heat release profiles were markedly different. Halogenated compounds can influence radiative thermal losses from flames through changes in flame structure that effect the temperature and soot concentration. Therefore, a small Schmidt-Boelter type gauge was used to measure the radiative flux through a cylindrical control volume surrounding the flame, and the total radiation emitted from the flame was calculated by integrating the emitted flux. The results show that as nitrogen was added to the methane-air base flame, the radiative heat loss fraction decreased slightly. When chloromethane was added to the oxidizer stream, the radiative heat loss fraction increased substantially.

• OSTI ID: 215689
• Journal Information: Combustion and Flame, Vol. 104, Issue 1-2; Other Information: PBD: Jan 1996
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
METHANE
COMBUSTION
FIRE EXTINGUISHERS
PERFORMANCE TESTING
CHLORINATED ALIPHATIC HYDROCARBONS
INHIBITION
COMBUSTION HEAT
FLAMES
MORPHOLOGY
RADIANT HEAT TRANSFER
HEAT LOSSES