Fluid Dynamic Aspect in the Heat Removal near the Spacer of the Fuel Rods of a Nuclear Reactor

核反应堆燃料棒间隔件附近散热中的流体动力学方面

基本信息

批准号：
61550131
负责人：
FUKANO Tohru
金额：
$ 1.22万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550131/
关键词：
Two-phase flow Film flow Spacer Obstacle Fuel rod 原子炉

项目摘要

In this research project (1) flow mechanism of a thin liquid film flowing concurrently with a high speed gas flow, (2) mechanism of a large disturbance wave generation, and (3) the interaction between a flat-plate type flow obstruction with a cylindrical projection and a thin liquid film, are investigated. The results are summarized as follows; (1) Although the film Reynold's number was 150 at the most in this research, the film flow is laminar only in the very narrow region close to the duct wall due to the momentum exchange between a gas flow and surface waves. Then the temperature boundary layer becomes extremely thin and the liquid film is easy to break by the accerelated evaporation. (2) The disturbance wave, which plays an important role in the formation of a liquid film, is generated when the velocity of the particles exceed that of thd wave at the interface. The boundary of the existence of the disturbace wave depends strongly on the pipe orientation in the low gas velocity region. (3) The projection attached to the flat plate has a strong effect on the liquid film breakdown, while the flat plate without a projection is effective to keep a thin liquid film near the obstacle. In the case with the projection three types of the film breakdown are observed, i.e (a) the upstrem-side film breakdown due to a horse shoe vortex just in front of the projection, (b) the downstream-side film breakdown extending far downstream of the obstacle and (c) the downstream-side film breakdown limited within the gap of the obstacle. These three types of the film breakdown will be a main factor to restrict the maximum heat removal of the nuclear reactor.

在这项研究项目（1）薄液膜与高速气流同时流动的流动机制，（2）大干扰波产生的机制，以及（3）扁平板型流动阻塞与圆柱体投影与薄液膜之间的相互作用。结果总结如下；（1）尽管在这项研究中，雷诺的数字最多为150，但由于气流和表面波之间的动量交换，薄膜流仅在靠近管道壁的非常狭窄的区域层流。然后，温度边界层变得非常薄，并且液膜很容易被加速的蒸发破裂。（2）当粒子的速度超过界面处的THD波的速度时，就会生成干扰波在形成液膜中起重要作用。干扰波的存在的边界在很大程度上取决于低气速区域的管道方向。（3）附着在平板上的投影对液体膜的崩溃具有很强的作用，而没有投影的平板有效地将稀薄的液体膜保持在障碍物附近。在预测的情况下，观察到了三种类型的薄膜崩溃，即（a）由于投影前方的马鞋涡流而导致的上游侧膜崩溃，（b）下游侧面胶片的损坏延伸到障碍物的下游远处，（c）（c）下游胶片损坏障碍物的差异限制。这三种类型的薄膜崩溃将是限制核反应堆最大热量的主要因素。