Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| Active control of flow and heat transfer in silicon microchannels | |
| Liu, Guohua1; Xu, Jinliang1; Yang, Yongping2; Zhang, Andwei2 | |
| 2010-04-01 | |
| 发表期刊 | JOURNAL OF MICROMECHANICS AND MICROENGINEERING
 |
| ISSN | 0960-1317 |
| 卷号 | 20期号:4页码:16 |
| 产权排序 | [Liu, Guohua; Xu, Jinliang] Chinese Acad Sci, Guangzhou Inst Energy Convers, Micro Energy Syst Lab, Guangzhou 510640, Peoples R China; [Yang, Yongping; Zhang, Andwei] N China Elect Power Univ, Beijing Key Lab New & Renewable Energy, Beijing 102206, Peoples R China |
| 通讯作者 | xjl@ncepu.edu.cn ; yyp@ncepu.edu.cn |
| 摘要 | Boiling heat transfer in silicon microchannels needs high walls and liquid superheats for bubble nucleation, leading to a strong thermal non-equilibrium between vapor and liquid phases, which not only damages the heat transfer device at the start-up stage, but also causes two-phase flow instabilities. In this paper, the seed bubble technique is used as an active control strategy to improve the flow and heat transfer in silicon microchannels. Seed bubbles are miniature bubbles of micron size, which are produced on a set of microheaters upstream of microchannels driven by pulse voltage signal. They flow downstream of microchannels after they depart from microheaters to decrease and control the thermal non-equilibrium between vapor and liquid phases in microchannels. The working fluid was methanol and the hydraulic diameter of the microchannels was 100 mu m. The demand curves of pressure drops versus mass fluxes were examined with and without active control. Four regions (I, II, III and IV) of demand curves were identified. For the flow without active control, the four regions were the subcooled liquid flow, the superheated liquid flow, the unstable boiling flow and the vapor flow at high-vapor-mass qualities. Alternatively, for the flow with active control, the four regions were the subcooled liquid flow, the seed-bubble-triggered boiling flow, the seed-bubble-stabilized boiling flow and the vapor flow at high-vapor-mass qualities. The linear part of the demand curves is shortened when the seed bubble technique is used. The points at which the demand curves deviate from the linear part coincide into one point at different seed bubble frequencies. The seed bubbles have no influence on the subcooled liquid flow (region I) and the vapor flow at high-vapor-mass qualities (region IV). However, seed bubbles not only convert a superheated liquid flow into a quasi-stable boiling flow in region II, but also convert an unstable boiling flow into a quasi-stable boiling flow in region III. Besides, heat transfer coefficients with active control are several times those without active control in regions II and III. The higher the seed bubble frequencies, the more the heater surface temperatures decrease. |
| 文章类型 | Article |
| 其他摘要 | Boiling heat transfer in silicon microchannels needs high walls and liquid superheats for bubble nucleation, leading to a strong thermal non-equilibrium between vapor and liquid phases, which not only damages the heat transfer device at the start-up stage, but also causes two-phase flow instabilities. In this paper, the seed bubble technique is used as an active control strategy to improve the flow and heat transfer in silicon microchannels. Seed bubbles are miniature bubbles of micron size, which are produced on a set of microheaters upstream of microchannels driven by pulse voltage signal. They flow downstream of microchannels after they depart from microheaters to decrease and control the thermal non-equilibrium between vapor and liquid phases in microchannels. The working fluid was methanol and the hydraulic diameter of the microchannels was 100 mu m. The demand curves of pressure drops versus mass fluxes were examined with and without active control. Four regions (I, II, III and IV) of demand curves were identified. For the flow without active control, the four regions were the subcooled liquid flow, the superheated liquid flow, the unstable boiling flow and the vapor flow at high-vapor-mass qualities. Alternatively, for the flow with active control, the four regions were the subcooled liquid flow, the seed-bubble-triggered boiling flow, the seed-bubble-stabilized boiling flow and the vapor flow at high-vapor-mass qualities. The linear part of the demand curves is shortened when the seed bubble technique is used. The points at which the demand curves deviate from the linear part coincide into one point at different seed bubble frequencies. The seed bubbles have no influence on the subcooled liquid flow (region I) and the vapor flow at high-vapor-mass qualities (region IV). However, seed bubbles not only convert a superheated liquid flow into a quasi-stable boiling flow in region II, but also convert an unstable boiling flow into a quasi-stable boiling flow in region III. Besides, heat transfer coefficients with active control are several times those without active control in regions II and III. The higher the seed bubble frequencies, the more the heater surface temperatures decrease. |
| 关键词 | Parallel Microchannels Boiling Instabilities |
| 学科领域 | Engineering ; Science & Technology - Other Topics ; Instruments & Instrumentation ; Materials Science ; Mechanics |
| WOS标题词 | Science & Technology ; Technology |
| DOI | 10.1088/0960-1317/20/4/045006 |
| 研究领域[WOS] | Engineering ; Science & Technology - Other Topics ; Instruments & Instrumentation ; Materials Science ; Mechanics |
| URL | 查看原文 |
| 关键词[WOS] | PARALLEL MICROCHANNELS ; BOILING INSTABILITIES |
| 收录类别 | SCI |
| 语种 | 英语 |
| 项目资助者 | National Natural Science Foundation of China [50825603] |
| WOS类目 | Engineering, Electrical & Electronic ; Nanoscience & Nanotechnology ; Instruments & Instrumentation ; Materials Science, Multidisciplinary ; Mechanics |
| WOS记录号 | WOS:000275841800007 |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.giec.ac.cn/handle/344007/8508 |
| 专题 | 中国科学院广州能源研究所 |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Energy Convers, Micro Energy Syst Lab, Guangzhou 510640, Peoples R China 2.N China Elect Power Univ, Beijing Key Lab New & Renewable Energy, Beijing 102206, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, Guohua,Xu, Jinliang,Yang, Yongping,et al. Active control of flow and heat transfer in silicon microchannels[J]. JOURNAL OF MICROMECHANICS AND MICROENGINEERING,2010,20(4):16. |
| APA | Liu, Guohua,Xu, Jinliang,Yang, Yongping,&Zhang, Andwei.(2010).Active control of flow and heat transfer in silicon microchannels.JOURNAL OF MICROMECHANICS AND MICROENGINEERING,20(4),16. |
| MLA | Liu, Guohua,et al."Active control of flow and heat transfer in silicon microchannels".JOURNAL OF MICROMECHANICS AND MICROENGINEERING 20.4(2010):16. |
| 条目包含的文件 | 下载所有文件 | |||||
| 文件名称/大小 | 文献类型 | 版本类型 | 开放类型 | 使用许可 | ||
| Active control of fl（2449KB） | 开放获取 | CC BY-NC-SA | 浏览 下载 | |||
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
修改评论