微通道内点面积热源汽泡动力学及对微换热器流动与传热的影响

GIEC OpenIR > 中国科学院广州能源研究所

	微通道内点面积热源汽泡动力学及对微换热器流动与传热的影响
其他题名	Dot-heating bubble dynamics in microchannels and its effect on flow and heat transfer of microheat exchanger
	李倩
导师	徐进良
	2009-06-02
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
学位专业	工程热物理
关键词	流动沸腾 Mems 微汽泡动力学 Marangoni 效应 Flow Boiling Microbubble Dynamics Marangoni Effect
摘要	The present study used the microfluidic chip fabricated by standard MEMS technology to investigate typical microscale phase change phenomena with acetone as the working fluid. The results showed that the microbubble’s growth and oscillation were influenced by heat power, mainstream mass flow and condensate depression in cold position; Meanwhile, there existed two-dimensional oscillation when growing on the microheater with the mass flowrate as the main factor. When there were heat flux on the rearface heater, the disengaged seed bubbles would trigger ebullition in microchannels, which would strengthen heat transfer, enhance temerature field uniformity and inhibit boiling instability. At the same time, flow patterns would also affect seed bubbles on Pt heater. With the heat flux of rearface heater increasing, three representative types of microbubbles are identified on the microheater, correspongding to three surging tendency. The conclusions indicate that transitions among these bubbles and various departure modes strongly depend on the instability of flow boiling in microchannels. The research not only lays the foundation for getting rid of burnout and boiling instability, but also improves system integration.
其他摘要	本研究在微流体光学平台上利用脉冲控制热源产生微汽泡，当通道处于冷态时，发现了影响汽泡生长延迟及脱离的因素；汽泡在膜上生长时伴随着二维跳跃，且主流流量的提高会抑制汽泡的振动；热控下脱离热源的汽泡会在较低的过热度下引发微通道内的沸腾相变，强化传热的同时提高了芯片温度场的均匀性，并能抑制沸腾的不稳定性。同时，沸腾流型会使加热元上出现三种代表性的汽泡动力学特性。分析表明，微通道内不稳定流动沸腾的振动流态，是铂膜上形成各种泡并以不同方式脱离的原因。研究为避免微传热系统启动时烧毁以及减弱甚至消除系统的不稳定性奠定了基础，提高了微换热系统与电子芯片的系统集成性。
页数	67
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/5838
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	李倩. 微通道内点面积热源汽泡动力学及对微换热器流动与传热的影响[D]. 广州能源研究所. 中国科学院广州能源研究所,2009.

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
200628014924001李倩_pa（13388KB）			开放获取	CC BY-NC-SA	浏览下载