环形燃料流量分配比范围研究

针对环形燃料双冷却通道的特殊结构形式，基于计算流体力学（CFD）方法建立了单棒精细化流固热耦合数值计算模型，通过计算内外包壳与内外通道冷却水的温度场分布对环形燃料流量分配比（φ）的取值范围进行了研究。计算结果表明：内外包壳温差与内外通道出口温差均随着φ的增大而减小；当φ≤0.72时，外包壳内部径向温度曲线斜率在包壳表面附近出现陡变；0.86≤φ≤1时，包壳内部温度变化均匀，无温度陡变现象，且内外包壳温差小于8 ℃，内外通道出口冷却水温差小于10 ℃。综合考虑环形燃料双侧冷却优势的充分发挥和包壳的机械安全性，确定了φ的取值范围为0.86～1。

Study on Flow Distribution Ratio Range of Annular Fuel

Annular fuel has a special configuration of dual cooling channel. In this paper, based on computational fluid dynamics （CFD） method, a detailed fluid-solid-thermal coupling numerical calculation model for single annular fuel rod was established. The value range of flow distribution ratio (φ) of annular fuel was studied by calculating the temperature distribution of internal/external cladding and internal/external channel cooling water. The results show that the internal/external cladding temperature difference and the internal/external channel outlet temperature difference decrease with the increase of φ. The slope of the radial temperature curve inside the cladding appears abrupt change near cladding surface when φ≤0.72. And the temperature change inside the cladding is uniform with no sharp temperature change phenomenon when 0.86≤φ≤1. Moreover, the internal/external cladding temperature difference is less than 8 ℃, and the internal/external channel outlet temperature difference is less than 10 ℃. Considering the advantages of bilateral cooling capacity and the mechanical safety of the cladding, the value range of φ is determined to be 0.86-1.