肋片对圆环通道内超临界水传热特性影响的数值分析

以计算流体力学(CFD)商业软件CFX为计算平台,对圆环通道内超临界水(SCW)的传热特性进行数值模拟。通过对几种湍流模型的对比,选取对超临界条件适用性相对较好的SST模型进行计算;比较光滑圆环通道与带肋片圆环通道内的壁温分布及传热系数的变化;研究肋片形状、高度、间距及宽度等因素对传热特性的影响。结果表明:圆环通道内肋片的存在会导致局部传热强化;在本文计算的尺寸范围内,肋片形状和宽度对传热的影响很小;一定范围内,增加肋片高度以及减小肋片间距都有利于传热强化。

Numerical Simulation of Supercritical Water Heat Transfer Characteristics in Annular Channel

A numerical simulation was carried out to study the heat transfer characteristics of supercriti-cal water in annular channel using CFX 11.0.Wall temperature and heat transfer coefficient variation trends in smooth annular channel were compared with those in annular channel with ribs.The shape,height,distance and thickness of ribs were studied as the important influence factors on heat transfer of supercritical water in this paper.The results show that local heat transfer enhancement occurs near ribs.It also can be found that the effect of rib shape on heat transfer is negligible.Increasing the ribs height and decreasing the ribs distance are good for improving heat transfer in a certain range.The effect of rib width on heat transfer is also negligible in a certain range.