球床内流动与传热特性等效模型的优化研究

Optimization Study on Flow and Heat Transfer in an Equivalent Model for Sphere Bed

提出研究球形燃料元件水冷堆热工．水力问题的等效模型方法。运用计算流体力学软件对窄间隙带环肋片细棒束结构进行三维建模、网格划分和流动传热模拟计算，得到表观流速在0．076-4）．334m／s范围内的压降和换热系数，并与已有的球床实验数据进行比较。根据比较结果对等效模型几何参数进行优化，得到最优等效模型。研究结果表明：最优等效模型与球床的流动与传热特性一致，从数值方法上证明采用等效模型方法对球形燃料元件水冷堆热工．水力问题进行研究是可行的。

An equivalent model methodology for studying the thermal-hydraulics problems of spherical fuel assembly water cooled reactor is proposed. In this paper, 3D geometry modeling, meshing and simulation calculation of flow and heat transfer for narrow-gap small bundle with annular f＇ms are performed with computational fluid mechanics software, and the pressure drop and heat transfer coefficient with the velocity ranged from 0.076 to 0.334 m/s are obtained and compared with the existing experimental data for sphere bed. Based on comparison results, geometrical parameter for the equivalent models is optimized to get the most optimized equivalent model. The study result shows that the most optimized model is equivalent to sphere bed on characteristics of flow and heat transfer, and proves the feasibility to study the thermal-hydraulics problems of spherical fuel assembly water cooled reactor by the equivalent model methodology.