Temperature Visualization of Fluidizing Particles and Construction of a Heat Transfer Model in a Fluidizing Bed Heat Exchanger.

流化颗粒的温度可视化和流化床换热器传热模型的构建。

基本信息

批准号：
11650215
负责人：
YAMADA Jun
金额：
$ 2.24万
依托单位：
Yamanashi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650215/
关键词：
Fluidized Bed Temperature Visualization Heat Transfer Enhancement Heat Exchanger 伝熱促進機構

项目摘要

This study deals with the heat transfer mechanisms at a microscopic level. Heat conduction during contact between a heat transfer surface and fluidizing particles, which is one of the effective heat transfer mechanisms in a gas-solid fluidized bed, has been empirically investigated. The temperatures of the fluidizing particles during the contact period is visualized with the aid of an infrared imager. This visualization reveals that the particles have been considerably heated in the thermal boundary layer on the heat transfer surface before contact. Based on the visualized temperature of the particles, the contact conductance between a fluidizing particle and the heat transfer surface is estimated by inverse analysis, and using the evaluated contact conductance, the contributions of the conductive heat transfer to the total heat transfer are also evaluated.In order to evaluate the contributions of the conductive heat transfer to a tube type heat transfer surface that is popular in practical fluidized beds, the validity of a heat transfer experiment that uses two types of spherical particles is evaluated. These particles used in the experiment are made of glass and aluminum and have the same diameter. Since the particles have almost the same density but deferent thermal conductivity, the deference of the total heat transfer is considered to correspond to the contributions of the conductive heat transfer. The contributions estimated for the same heat transfer surface as the visualization are in good agreement with those estimated by the visualization. Using the two types of particles, the contributions of the conductive heat transfer on a tube-type heat transfer surface are evaluated in a various fluidizing conditions.

这项研究涉及微观水平的传热机制。在传热表面和流化颗粒之间接触期间的热传导，这是气体固定床中有效的传热机制之一。借助红外成像仪，可以在接触周期内观察流化颗粒的温度。这种可视化表明，在接触之前，在热传递表面的热边界层中已经大量加热了颗粒。根据颗粒的可视化温度，通过反向分析估算流动颗粒与热传递面之间的接触电导率，并使用评估的接触电导率，还评估导电热传递对总热传递的贡献。按顺序进行评估。以评估导电性传热表面对实践流动性的流动性传热型的导电性传热表面的贡献评估。实验中使用的这些颗粒由玻璃和铝制成，并具有相同的直径。由于颗粒具有几乎相同的密度但递延的热导率，因此总热传递的尊重被认为与导电热传递的贡献相对应。与可视化相同的传热表面估计的贡献与可视化估计的贡献非常吻合。使用两种类型的颗粒，在各种流化条件下评估了导电传热在管型传热面上的贡献。