摘要
为了准确测量微管外表面温度场的分布,并解决沿微管轴向导热对微管内部对流换热的影响,本文把非接触式测量温度方法引入到微尺度实验中.本次研究搭建了能够进行气体、液体流动与换热的微流动实验台,用蒸馏水作为工质,采用红外成像仪加专用红外放大镜头对微型钢管表面温度场作了可视化实验研究,得到了在Re数不变时,不同加热功率下内直径为168μm和外直径为406μm微型钢管外表面温度场的分布图,进而得到了沿轴向温度对沿轴向长度的二次导数.建立简化的数学模型,并通过推导获得了沿轴向的导热对内部对流换热的关系式.实验与理论推导结果表明,在微圆管单相流情况下,其轴向的导热对管内对流换热影响很小,可以忽略不计.
To accurately measure the surface temperature field of the microtube and solve the influence of axial heat conduction along the wall of the microtube on convective heat transfer in the microtube, non-contact temperature measuring method is firstly used in the microscale experiment. An experimental test loop, which can conduct some tests about micro-heat transfer and micro-flow for gas and liquid, is established. When distilled water is used as the working fluid and flowing through the microtube, a visual experiment about the surface temperature field is conducted, that is, the surface temperature field photos of microtube with inner diameter of 168μm and outer diameter of 406μm were acquired by employing the infrared thermoviewer and a specially magnifying lens for the constant Re number and different heating powers. Further, the second order derivative about the temperature along the axial microtube to the length is obtained. A simple mathematic model is set up and the correlation between the axially conductive heat and inner convective heat transfer is obtained by derivation. The experimental results and the theoretical analysis show that the quantity of axial heat conduction is considerably small and may be neglected compared to the convective heat transfer in the condition of single-phase.
出处
《中国科学院研究生院学报》
CAS
CSCD
2006年第3期317-322,共6页
Journal of the Graduate School of the Chinese Academy of Sciences
关键词
微尺度传热
微流动
微管
红外成像仪
micro-transfer heat, micro-flow, microtube, infrared thermoviewer
