Control of Heat Transfer and Defrostings with Fluidized Beds

流化床传热和除霜的控制

基本信息

批准号：
06044018
负责人：
AIHARA Toshio
金额：
$ 3.84万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044018/
关键词：
Fluidized bed Impinging jet Heat-transfer control Frosting control Cooled tube array 冷却官群

项目摘要

In the cases where conventional finned-tube heat exchangers are used as evaporators in heat pump systems and LNG-gasification systems, moisture in humid air freezes and forms a thick frost layr on the fin surfaces, which reduces the heat transfer, increases the pressure loss, and finally results in choking of the evaporatores. Thus development of frost-free evaporators is an important and urgent research subject. The present research project has been performed to study heat and mass transfer characteristics of impinging jet-type fluidized bed and its defrosting characteristics. The obtained results are useful to establish a fluidized-bed heat exchanger which is effective for defrosting.Results of the Joint ResearchIn Tohoku University, the following experimental studies were performed :(1) Study on local heat transfer and frosting characteristics of cold tubes in single-phase impinging jets.(2) Study on defrosting mechanism of a very shallow fluidized bed, measurement of particle's con … More tact frequency onto the tube surface, and observation of the behavior of particles on the tube surface.(3) Study on heat transfer characteristics of cold tubes under defrosting by particle impingement.In Hokkaido University the following experimental studies were performed :(1) Study on heat transfer charactersistics of impinging-jet type fluidized ged. Especially the effect of fluidizing particles on heat transfer in a powder-mixed fluidized bed.(2) Study on freezing and continuous production characteristics of liquid ice by use of the fluidized bed.(3) Study on frosting characteristics of a vertical cooled plate and a horizontal cooled tube array immersed in a fluidized bed.(4) Study on melting heat transfer characteristics of a horizontal cooled tube array immersed in liquid ice.In Technical University, Vienna, theoretical study on formation process of particle-gas jets and their impingement onto tube surface was performed especially for the cornice-type distributor, utilized in Tohoku University.By joining these results of the above-mentioned studies, an potimum design method for impinging-jet type fluidized bed has been established. Also the heat-transfer and defrosting characteristics and the control theory for them were clarified, which is useful for practical applicatios. Less

在连接管热交换器是热泵系统中的蒸发器和液化天然气加热系统中的蒸发器的情况下，d空气冻结并在鳍片表面形成了最终的路线，从而降低了热传递，增加了压力损失，最终导致chover缩。自由蒸发器的蒸发是重要的紧急研究主题。在联合重新分校的大学中，进行了以下实验研究：（1）研究局部热管的局部热传递和糖化的糖化特征。 . (3) Study on. Heat Transfer Characteristics of Cold Tubes by Particle Impingement.in HOKKAIDO UNIVERSITY THE FOLLOWING EXPERIMEL STUDIES WERE RMED: (1) Study On Heat TransferSistics of Impinging-Jet FLUIDIZED GED. Owder -mixed Fluidized Bed. Incteristics of a垂直冷却的板和水平冷却的管阵列浸入流动性床（4）研究。 - 在Tohoku大学中使用的to材料。通过加入上述研究的结果，还建立了热量转移和解冻特征