• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Heat and Mass Transfer >Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions
【24h】

Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions

机译：平行微通道中的瞬态流型和气泡段长，其中催化化学反应产生的氧气气泡

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Transient flow patterns and bubble slug lengths were investigated with oxygen gas (O_2) bubbles produced by catalytic chemical reactions using a high speed camera bonded with a microscope. The microreactor consists of an inlet liquid plenum, nine parallel rectangular microchannels followed by a micronozzle, using the MEMS fabrication technique. The etched surface was deposited by the thin platinum film, which is acted as the catalyst. Experiments were performed with the inlet mass concentration of the hydrogen peroxide from 50% to 90% and the pressure drop across the silicon chip from 2.5 to 20.0 kPa. The silicon chip is directly exposed in the environment thus the heat released via the catalytic chemical reactions is dissipated into the environment and the experiment was performed at the room temperature level. It is found that the two-phase flow with the catalytic chemical reactions display the cyclic behavior. A full cycle consists of a short fresh liquid refilling stage, a liquid decomposition stage followed by the bubble slug flow stage. At the beginning of the bubble slug flow stage, the liquid slug number reaches maximum, while at the end of the bubble slug flow stage the liquid slugs are quickly flushed out of the microchannels. Two or three large bubbles are observed in the inlet liquid plenum, affecting the two-phase distributions in microchannels. The bubble slug lengths, cycle periods as well as the mass flow rates are analyzed with different mass concentrations of hydrogen peroxide and pressure drops. The bubble slug length is helpful for the selection of the future microreactor length ensuring the complete hydrogen peroxide decomposition. Future studies on the temperature effect on the transient two-phase flow with chemical reactions are recommended.
机译：使用显微镜结合的高速相机，通过催化化学反应产生的氧气（O_2）气泡研究了瞬态流动模式和气泡段长。该微反应器由入口液体增压室，九个平行的矩形微通道和随后的微喷嘴组成，采用MEMS制造技术。蚀刻的表面由薄铂膜沉积，该铂膜充当催化剂。在过氧化氢的入口质量浓度为50％至90％，硅芯片上的压降为2.5至20.0 kPa的条件下进行实验。硅芯片直接暴露在环境中，因此通过催化化学反应释放的热量散发到环境中，并且实验在室温下进行。发现具有催化化学反应的两相流表现出循环行为。一个完整的周期包括一个短暂的新鲜液体补充阶段，一个液体分解阶段，随后的气泡团流动阶段。在气泡团流动阶段的开始，液体团的数量达到最大值，而在气泡团流动阶段的末尾，液体团迅速被冲出微通道。在入口液室中观察到两个或三个大气泡，影响了微通道中的两相分布。使用不同质量浓度的过氧化氢和压降来分析气泡塞长度，循环周期以及质量流率。气泡塞长度有助于选择未来的微反应器长度，从而确保过氧化氢完全分解。建议进一步研究温度对具有化学反应的瞬态两相流的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号