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Microscopic Measurement of Particle Laden with aHigh Teperature Gas Flow by Using a Fluorescet Method

荧光法对高温气流中载有颗粒的显微测量

基本信息

批准号：
04650176
负责人：
SATOH Isao
金额：
$ 1.34万
依托单位：
Toky Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650176/
关键词：
Gas-Solid Suspension Flow Time-Dependent Temperature ofa Particle Fluorescent Method Simultaneous Measurement of Temperature and Velocity Remote Heating Effective Thermal Conductivity 温度履歴計測 LDV 同時計測

项目摘要

The final goal of this study is to obtain better understandings of the temperature of fine particles laden with a high temperature gas fow ( a gas-solid suspension flow), so as to estimate the heat transfer within the suspension fow including radiative heat exchange. In this research project, therefore, a microscopic measurement method for the particle temperature suspended in a gas flow was proposed. The proposed method is based on the "fluorescent method", which utilizes the temperature dependency of intensity and/or lifetime of the fluorescent light. Namely if a fluorescent particle is periodically excited by a blinking light, fluorescent light from the particle is also periodic but the phase of fluorescent light is shifted. The phase difference between the exciting and fluorescent lights is related to the lifetime of fluorescence, and thus temperature of the fluorescent particle can be determined by measuring the phase shift. In the present method, fluorescent particles were periodically excited by making them passed through fringes generated in the measuring volume of a Laser-Doppler Velocimetry (LDV). By using this method, velocity and temperature of individual particles can be simultaneously determined by measuring the frequency of scattered light and the phase shift of fluorescent light, respectively. A prototype measurement system was constructed, and the propriety of the present method was confirmed by measuring the temperature and velocity fields in a simpe gas-slid suspension flow.In addition to this, diffusion of heat within a fluidized partcle layr was experimentaly examined ; the particle layr was reotely heated by using a CO_2 gas laser, and time-dependent temperature distributions were mesured by means of a IR thermograph. The results clearly showed that the effective thermal conductivity of thefluidized particle layr is a value of te order of 5 W/mK, which is smaller than the values reprted in literature.

本研究的最终目的是为了更好地了解高温气体FOW(气固悬浮流)中细颗粒的温度，从而估算包括辐射换热在内的悬浮FOW内的换热。因此，在本研究项目中，提出了一种测量气流中悬浮颗粒温度的微观测量方法。该方法是在“荧光法”的基础上提出的，该方法利用了荧光灯强度和/或寿命的温度依赖性。也就是说，如果一个荧光粒子被闪烁的光周期性地激发，那么来自该粒子的荧光光也是周期性的，但荧光的相位发生了移位。激发光和荧光光之间的相位差与荧光的寿命有关，因此可以通过测量相移来确定荧光粒子的温度。在本方法中，通过使荧光粒子通过激光多普勒测速仪(LDV)测量体积中产生的条纹来周期性地激发荧光粒子。利用这种方法，可以通过测量散射光的频率和荧光的相移来同时测量单个粒子的速度和温度。搭建了一套原型测量系统，通过对SIMPe气液两相流中的温度场和速度场的测量，验证了该方法的正确性，并对流态化颗粒层内的热扩散进行了实验研究，利用CO_2气体激光器对颗粒层进行了重复加热，并用红外热像仪测量了颗粒层内的温度随时间的分布。结果表明，流态化颗粒层的有效导热系数为5W/mK数量级，比文献中的计算值要小。