High Density Array of Tubes in Horizontal Tube-Bundle Evaporator

卧式管束蒸发器中的高密度管阵列

基本信息

批准号：
05555067
负责人：
FUJITA Yasunobu
金额：
$ 4.42万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05555067/
关键词：
Boiling in Tube Bundle Nucleate Boiling In-line Array Staggered Array Critical Heat Flux 高密度管配列

项目摘要

An experimental study on nucleate boiling heat transfer was performed to investigate various effects on heat transfer characteristics in horizontal tube bundle and to gain useful information for developing an evaporator with horizontal tubes more densely arrayd. Experiments were done for in-line and ataggered tube arrangement under the conditions of natural circulation and forced circulation of fluid within a tube bundle. Findings are as follows.(1) Compared with the performance of a single horizontal tube in pool boiling, heat transfer coefficient of tube bundle shows the same level at higher heat flux where nucleate boiling is fully established, while at lower heat flux the boiling heat transfer is highly enhanced in a bundle.(2) The above mentioned difference in performance between a single tube and a tube bundle is true for both bundles of in-line and staggered arrangement.(3) Under the condition of natural circulation a rise of heat transfer coefficient at lower heat flux is more enhanced as the location of tube is higher in a bundle.(4) In the case of forced circulation, heat transfer coefficient at lower heat flux increases with an increase of circulating flow velocity. Heat transfer coefficient increases vertically at first for lower tubes, then decreases for higher tubes.(5) As for an effect of tube pitch, a pitch to diameter ratio P/D of 1.5 shows better performance under the natural circulation, while a P/D of 1.3 is preferable for the forced circulation.

进行了一项关于成核沸腾传热的实验研究，以研究水平管束中对传热特征的各种影响，并获得有用的信息，以开发带有水平管的蒸发剂更密集的阵列。在自然循环的条件下，进行了串联和agger的试管布置实验，并在管束中的流体循环进行了实验。发现如下。（1）与单个水平管在池中的表现相比，管束的传热系数显示在较高的热量下完全建立了核沸腾的沸腾水平相同的水平，而在较低的热通量下，沸腾的热传递在束中高度增强。布置。（3）在自然循环的条件下，由于管子的位置在捆绑中的位置较高，因此在较低热通量下的传热系数的上升更加增强。（4）在强制循环的情况下，较低热通量处的热传递系数随着循环流速的增加而增加。对于较低的管，最初垂直增加了传热系数，然后减少较高的管子。（5）与管螺距的效果相比，在自然循环下，螺距与直径比为1.5的p/d显示出更好的性能，而P/d的P/D为1.3，为1.3均为强制循环。