Research of Key Radicals for Plasma Chemical Reaction in Atmospheric Pressure Discharges

常压放电等离子体化学反应关键自由基的研究

基本信息

批准号：
17360127
负责人：
KANAZAWA Seiji
金额：
$ 9.56万
依托单位：
Oita University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360127/
关键词：
Discharge Plasma Laser-Induced Fluorescence Environmental Protection OH Radical Streamer

项目摘要

Streamer coronas at atmospheric pressure are widely used in the non-thermal plasma processing of harmful gases. It is well known that hydroxyl (OH) radicals play an important role for the plasma chemical reactions in the reactor. Therefore, the direct study of the radicals in non-thermal plasma reactors is of great interest. Laser-induced fluorescence (LIF) is a useful diagnostic method for in-situ observation of the phenomena during the non-thermal plasma processing of gaseous pollutants.The OH radicals generated by the discharges have time transient characteristics (i.e. there are generation period and decay period during/after the discharge), and the lifetime is very short. While the DC streamer corona discharge consists of more of less regular self-repetitive current pulses (streamers) with the pulse duration up to several hundred nanoseconds and repetition frequency in the range of 1 to 100 kHz. In this study, taking into account on these time dependent characteristics, the time-r … More esolved and time-averaged behaviors of OH radicals were investigated.The LIF detection of the OH radicals was performed in the nozzle-to-plane electrode configuration (the radical injection and radical shower systems) during the steady-state positive streamer corona discharge at atmospheric pressure. For monitoring the ground-state OH radicals, the scheme with excitation at 282 nm and detection at 309 nm was used. The time relationship between the regular streamer coronas, laser pulse, OH fluorescence and laser-induced streamer was measured. The time dependence of OH radicals between the successive streamers was measured for the evaluation of OH dynamics. The two-dimensional OH distribution around the streamer corona region was also observed. As a result, it was found that the LIF could apply to the measurement of OH radicals generated by a DC streamer corona discharge at atmospheric pressure. The ground-state OH radicals were generated and stayed mainly in the region where streamers propagated between the electrodes. Less

常压下的流光电晕广泛应用于有害气体的非热等离子体处理，众所周知，羟基（OH）自由基在反应器中的化学等离子体反应中发挥着重要作用，因此对自由基的直接研究。激光诱导荧光 (LIF) 是一种用于原位观察气态污染物非热等离子体处理过程中现象的有用诊断方法。放电产生的电流具有时间瞬态特性（即放电期间/放电后有产生期和衰减期），寿命很短，而直流流电晕放电由较多不规则的自重复电流脉冲（流光）组成。），脉冲持续时间高达数百纳秒，重复频率在 1 至 100 kHz 范围内。在这项研究中，考虑到这些时间相关特性，时间 r … More 的解析和时间平均行为。研究了 OH 自由基。在大气压下稳态正流光电晕放电期间，在喷嘴平面电极配置（自由基注入和自由基喷淋系统）中进行了 OH 自由基的 LIF 检测，以监测地面。状态OH自由基，采用282 nm激发和309 nm检测的方案测量了规则流光电晕、激光脉冲、OH荧光和激光诱导流光之间的时间依赖性。测量连续流带之间的 OH 自由基以评估 OH 动力学，还观察了流带电晕区域周围的二维 OH 分布，结果发现 LIF 可应用于产生的 OH 自由基的测量。通过大气压下的直流流光电晕放电产生基态OH自由基，并主要停留在电极之间流光传播的区域。