标志球法1m和2m本体二维球流运动特性分析与比较

Analysis and Comparison of Pebble Flow Dynamics in 1 m and 2 m Two-Dimensional Experimental System with Marking Pebble Method

为研究球床高度对球流运动特性的影响,根据相似准则的原理建立高温气冷堆二维堆芯的球流运动试验系统,利用标志球的实验方法对球流运动规律进行研究。对1 m和2 m本体球流运动的均值流线、内部流场、标志球的平均滞留时间,以及交混区的球流的分布特征和分布区域等进行比较分析。结果表明:二维流动均值流线是光滑对称的流线型,球床边缘和中心的流动相差很大,球床下部的流动不均匀性比上部不均匀性大;增大装球高度球流可以达到更大的分散程度。验证交混区球的高斯分布;标志球的运动区域具有两头小中间大的特点;2 m本体的球床下部的流动均匀性优于1 m本体。

To study the height effect of the pebble flow dynamics, a 2-D pebble-bed experimental system for High Temperature Gas-cooled Reactor （HTGR） has been established based on the similarity criteria to study the pebble flow by using the marking pebble method. The characteristics of mean stream line, inner flow distribution, mean stagnant time, and distribution of the pebbles in the mixing zone of the lm and 2m experimental system have been discussed and compared. The results show that the mean streamline is smooth and symmetrical and the flow characteristics in the side area and the central region are greatly different. The pebble flow in the lower zone of the experiment set is more nonuniform than that in the upper zone. The degree of dispersion can be enlarged by increasing the height of the bed. These results validate the Gaussian Probability Distribution of pebble in the mixing zone. The moving area of the marking pebble has a wide middle section and narrow head and end sections. The degree of dispersion is larger in the higher bed than that in the lower bed.