Superiority of oxygen as feedstock for a plasma jet igniter in supersonic methane/air streams
Superiority of oxygen as feedstock for a plasma jet igniter in supersonic methane/air streams
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氧气作为超音速甲烷/空气流中等离子射流点火器原料的优越性
DOI：
10.1016/s1540-7489(02)80112-2
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Tachibana
中科院分区：
文献类型：
--
作者：
K. Shuzenji;T. Tachibana
等离子体射流点火试验进行了N2，O2，和空气原料，以澄清自由基在甲烷/空气反应中发挥更重要的作用。在马赫数为2、总温为400 K的试验条件下，通过改变电输入功率和给料流量测量了点火极限。实验结果表明，氧气等离子体射流的燃烧性能上级氮气和空气等离子体射流，当氧气流量为60 L/min时，点火极限输入功率约为0.7kW，仅为空气等离子体射流的13%。光谱测量揭示了存在的自由基，如氮和氧原子的火炬废气中，并确定了甲烷/空气和自由基的等离子体射流的反应所产生的化学物质。化学中间产物的变化很大，这取决于所添加的自由基是氧原子还是氮原子;氧原子产生H和OH，这是提高反应速率的重要物种。这些结果表明，氧等离子体射流点火的优越性是由于在射流中产生的自由基的化学效应，因此，氧原子是特别有效的甲烷/空气从反应的观点。
Ignition tests by plasma jets were conducted with N2, O2, and air feedstocks to clarify what radicals play a more important role in methane/air reaction. Under test conditions of flow Mach 2 and total temperature of 400 K, ignition limits were measured by changing the electrical input power and feedstock flow rates. The experimental results indicated that oxygen plasma jets were superior to nitrogen or air plasma jets, and when the oxygen feedstock flow rate was 60L/min, the input power at ignition limits was about 0.7 kW, only 13% of the value using air as the feedstock. Spectroscopy measurements revealed the presence of radicals such as nitrogen and oxygen atoms in the torch exhausts and identified the chemical species produced by the reactions of methane/air and radicals by plasma jets. The chemical intermediate products were greatly changed depending on whether the added radical was an oxygen atom or a nitrogen atom; oxygen atoms generated H and OH, important species for augmentation of the reaction rates. These results show that the superiority of oxygen plasma jets for ignition is due to the chemical effect of radicals produced in the jet, and accordingly that oxygen atoms are particularly effective in methane/air from reaction standpoints.