Evaluations for Fire-Suppression Abilities and Inhibition Reaction Mechanisms of Halon Replacements in Low-Temperature Combustion
| Project/Area Number |
16560194
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Sophia University |
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Principal Investigator |
TAKAHASHI Kazuo Sophia University, Faculty of Science and Technology, Lecturer (10241019)
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| Co-Investigator(Kenkyū-buntansha) |
猪俣 忠昭 上智大学, 理工学部, 教授 (30053656)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Halon Replacements / Hydrofluorocarbons / Rapid Compression Machine / Shock Tube / Turbulent Flow Reactor / Induction Period for Ignition / Reaction Intermediates / Low-Temperature Combustion / ヘプタン / HFC227ea / GC-MS / ハロン代替消化剤 / 熱分解反応 / 乱流流通反応管 / 反応速度 / 反応経路 / ヘプタフルオロプロパン / 負の温度計数領域 / 燃焼抑制 |
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| Research Abstract |
In this research project, the evaluations for fire-suppression abilities and the inhibition reaction mechanisms of hydrofluorocarbons, which are ones of the halon replacements, have been investigated at temperatures lower than 1000 K. A rapid compression machine was newly manufactured for this research project, in addition to a shock tube and a turbulent flow reactor.
In the ignitions of isobutane, the induction periods for ignition monotonically decreased with temperature. When HFC-227ea (2H-heptafluoropropane, CF_3CHFCF_3) was added in the mixtures of isobutane and air, the ignitions were suppressed. However, this inhibition effect was not caused by the deactivation of chain-carriers by fluorine atoms, because fluorine-free propane had the same inhibition effect as HFC-227ea.
In the ignitions of n-heptane, a negative temperature coefficient (NTC)region, where the induction periods increased with temperature, was observed. The addition of HFC-227ea gave the promotion for the n-heptane ignitions, in contrast to the isobutane ignitions. In the NTC region, oxygen molecules are added to alkyl radicals formed from fuel, so that alkylperoxy radicals (ROO) are produced. The alkylperoxy radicals are changed to hydroperoxyalkyl radicals (R'OOH) by the migration of H atoms. If HFC-227ea is added, the alkylperoxy radicals abstract H atoms from HFC-227ea to become peroxides. The peroxides docompose into OH radicals which are among the important chain-carriers in combustion, leading to the promotion of ignitions.
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Report
(4 results)
Research Products
(25 results)
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[Journal Article] Thermal Decompositions of 1, 1, 1-Trifluoroethane and Pentafluoroethane in a Turbulent Flow Reactor2007
Author(s)
K., Takahashi, A., Harada, S., Horigome, R., Cho, T., Inomata
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Journal Title
Combustion Science and Technology 179
Pages: 1417-1432
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Studies on the Ignitions of Heptane, Iso-Octane, Toluene, and Their Miixtures Behind Shock Waves2006
Author(s)
K., Tomiyasu, R., Cho, K., Takahashi, M., Kogoma, T., Inomata
Organizer
The Forty-Fourth Symposium(Japanese) on Combustion
Place of Presentation
Hiroshima, Japan
Description
「研究成果報告書概要(欧文)」より
Related Report
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