三角形子通道超临界水热工水力特性数值分析  

Numerical Analysis of Thermal-Hydraulic Behavior of Supercritical Water in Square Sub-Channels

作　　者：顾汉洋[1] 杨燕华[1] 程旭[1] 

机构地区：[1]上海交通大学核科学与工程学院,上海200240

出　　处：《核动力工程》2008年第4期50-56,共7页Nuclear Power Engineering

基　　金："973计划"项目(No.2007CB209804)资助

摘　　要：目前国际上对超临界水冷堆进行了大量的研究,但对其堆芯内超临界流体流动传热的认识还十分有限。本文采用CFX对超临界水冷堆典型三角形子通道内的流动传热特征进行了CFD研究,对比分析了包壳壁面等热流密度和燃料芯块等体积热流密度两种情况。计算结果表明,不锈钢包壳层的周向导热显著强化了燃料棒圆周上温度分布和传热系数的均匀性,但对二次流和湍流脉动的影响不大。间隙区的湍流脉动主要受几何参数P/D的影响,当P/D<1.3时,湍流交混系数在0.02～0.025之间,当P/D>1.3时,湍流交混系数较小,在温度拟临界点附近区域,存在交混系数的突变。Research activities are ongoing worldwide to develop nuclear power plants with a supercritical water cooled reactor （SCWR）. However, there is still a big deficiency in understanding and prediction of heat transfer in supercritical fluids. In this paper, thermal-hydraulic behavior of supercritical water in sub-channel of triangular-array rod bundle has been investigated using computational fluid dynamics（CFD） code CFX. Two cases, i.e. constant wall heat flux at cladding surface and constant volume heat density in fuel pellet, are analyzed. Results show that circumferential conduct heat transfer in cladding significantly reduces the non-uniformity of circumferential temperature and heat transfer distributions, but the conduct heat transfer is with weak effect on second flow and velocity fluctuation across the gap. Turbulence mixing at rod gap strongly depends on pitch-to-diameter ratio（P/D）. If P/D〈1.3, the mixing coefficient is in the range of 0.02 - 0.025. It also shows unusual behavior of mixing coefficient in the vicinity of the pseudo-critical point and needs further investigations.

关 键 词：超临界水冷堆 三角形子通道 流动传热 CFD 包壳层 燃料芯块 

分 类 号：TK123[动力工程及工程热物理—工程热物理]