Process of Pulsed Electrical Breakdown in High-Pressure Carbon Dioxide Including Supercritical Phase

カテゴリ: 研究会(論文単位)

論文No: PPT10051

グループ名: 【A】基礎・材料・共通部門 パルスパワー研究会

発行日: 2010/08/06

タイトル(英語): Process of Pulsed Electrical Breakdown in High-Pressure Carbon Dioxide Including Supercritical Phase

著者名: 喜屋武 毅(熊本大学),猪原 武士(熊本大学),亀田 卓(熊本大学),勝木 淳(熊本大学),原 雅則(熊本大学),秋山 秀典(熊本大学)

著者名(英語): Kiyan Tsuyoshi(Kumamoto University),Ihara Takeshi(Kumamoto University),Kameda Suguru(Kumamoto University),Katsuki Sunao(Kumamoto University),Hara Masanori(Kumamoto University),Akiyama Hidenori(Kumamoto University)

キーワード: 超臨界流体|二酸化炭素|ナノ秒パルス|ストリーマー|衝撃波|シャドウグラフ法|supercritical fluid|carbon dioxide|nano-second pulse|streamer|shock wave|shadowgraph method

要約(日本語): Applications of discharge plasmas to chemical reaction have been studied under various media such as atmospheric pressure gas, liquid and interfacial surface between gas and liquid by many researchers. These processes by discharge plasmas are classified into two types: high-energy electrons and radicals driven by non-thermal plasma; and activated ions and heat process driven by thermal plasma. Especially the streamer channel of non-thermal plasma is receiving particular attention as a source of active species for chemical reaction.In recent years, the discharge plasma in supercritical fluid has attracted increased attention from viewpoints both as a reaction process and as a discharge phenomenon. Owing to unique properties such as high diffusivity, high solubility and low viscosity, supercritical fluids have not only superior solvent power but also high reactivity. For the reasons mentioned above, the control and generation of non-thermal discharge plasma under supercritical conditions hold great potential as novel reaction process. That is, the discharge plasma aided reaction process would be realized without agitating supercritical conditions.The characteristics of direct current breakdown and pulsed electrical breakdown in supercritical carbon dioxide have thus far been investigated by the authors.In the present study, the process of pulsed electrical breakdown in high-pressure carbon dioxide is observed by means of the shadow graph method in order to clarify the pulsed discharge mechanism under supercritical conditions. A series of experiments is conducted by varying pressure from 0.1 to 10 MPa at the desired temperatures of 313 and 298 K. The discharge plasma process is observed by ICCD camera with Ar laser system. A magnetic pulsed compression with a step-up transformer is used as a pulsed generator, and high voltage pulse with the rising rate of 1kV/ns is applied to a needle-to-plate gap of 5 mm length. In this paper, newly observed phenomena in pulsed discharge process at three different phases will be reported.

要約(英語): Applications of discharge plasmas to chemical reaction have been studied under various media such as atmospheric pressure gas, liquid and interfacial surface between gas and liquid by many researchers. These processes by discharge plasmas are classified into two types: high-energy electrons and radicals driven by non-thermal plasma; and activated ions and heat process driven by thermal plasma. Especially the streamer channel of non-thermal plasma is receiving particular attention as a source of active species for chemical reaction.In recent years, the discharge plasma in supercritical fluid has attracted increased attention from viewpoints both as a reaction process and as a discharge phenomenon. Owing to unique properties such as high diffusivity, high solubility and low viscosity, supercritical fluids have not only superior solvent power but also high reactivity. For the reasons mentioned above, the control and generation of non-thermal discharge plasma under supercritical conditions hold great potential as novel reaction process. That is, the discharge plasma aided reaction process would be realized without agitating supercritical conditions.The characteristics of direct current breakdown and pulsed electrical breakdown in supercritical carbon dioxide have thus far been investigated by the authors.In the present study, the process of pulsed electrical breakdown in high-pressure carbon dioxide is observed by means of the shadow graph method in order to clarify the pulsed discharge mechanism under supercritical conditions. A series of experiments is conducted by varying pressure from 0.1 to 10 MPa at the desired temperatures of 313 and 298 K. The discharge plasma process is observed by ICCD camera with Ar laser system. A magnetic pulsed compression with a step-up transformer is used as a pulsed generator, and high voltage pulse with the rising rate of 1kV/ns is applied to a needle-to-plate gap of 5 mm length. In this paper, newly observed phenomena in pulsed discharge process at three different phases will be reported.

原稿種別: 日本語

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