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Evaluations for Fire-Suppression Abilities and Inhibition Reaction Mechanisms of Halon Replacements in Low-Temperature Combustion

哈龙替代品低温燃烧灭火能力及抑制反应机制评价

基本信息

批准号：
16560194
负责人：
TAKAHASHI Kazuo
金额：
$ 1.66万
依托单位：
Sophia University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560194/
关键词：
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 /

项目摘要

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.

在本研究项目中，对哈龙替代品氢氟烃在低于1000K的温度下的灭火性能进行了评价，并对其阻燃反应机理进行了研究。当HFC-227ea(2H-七氟丙烷，CF3CHFCF3)加入到异丁烷和空气的混合物中时，点火被抑制。但由于无氟丙烷具有与HFC-227e相同的缓蚀作用，这种缓蚀作用并不是由于氟原子对链载体的失活所致。在正庚烷的引燃过程中，观察到负温度系数(NTC)区，诱导期随温度的升高而增加。HFC-227ea的加入对正庚烷的引燃有促进作用，而对异丁烷的引燃有促进作用。在NTC区域，氧分子被添加到燃料形成的烷基自由基中，从而产生烷基过氧基(RoO)。通过H原子的迁移，烷基过氧基转变为氢过氧烷基(R‘OOH)。如果加入HFC-227ea，烷基过氧基将HFC-227ea中的H原子提取为过氧物。在燃烧过程中，过氧化氢生成的OH自由基是燃烧过程中重要的链状载体，对着火有促进作用。

项目成果

期刊论文数量（33）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Shock-Tube Studies on the Fire-Suppression Reactions of HFC-227ea

HFC-227ea 灭火反应的激波管研究

DOI：
发表时间：
2005
期刊：
Twenty-Fifth Symposium(International)on Shock Waves
影响因子：
0
作者：
K.Takahashi;et. al.
通讯作者：
et. al.

Thermal Decompositions of 1,1,1-Trifluoroethane and Pentafluoroethane in a Turbulent Flow Reactor

1,1,1-三氟乙烷和五氟乙烷在湍流反应器中的热分解

DOI：
发表时间：
2007
期刊：
Combustion Science and Technology (In press)
影响因子：
0
作者：
Takei;Yasuhito;Takahashi;Nobuo;Nishimura;Hidekazu;Tajima;Hiroshi;Kazuo Takahashi et al.
通讯作者：
Kazuo Takahashi et al.

Studies on the Ignitions of Gasoline Components in a High Pressure Shock Tube

高压激波管内汽油元件的点火研究