花瓣形燃料元件棒束通道内过冷流动沸腾特性数值研究  

Numerical Investigation of Subcooled Flow Boiling Characteristics in Rod Bundle Channel of Petal-shape Fuel Element

作　　者：杜利鹏 蒋泽平[1,2] 崔军 张文超 侯延栋 蔡伟华[1,2] DU Lipeng;JIANG Zeping;CUI Jun;ZHANG Wenchao;HOU Yandong;CAI Weihua(Laboratory of Thermo-Fluid Science and Nuclear Engineering,Northeastern Electric Power University,Jilin 132012,China;School of Energy and Power Engineering,Northeastern Electric Power University,Jilin 132012,China;China Nuclear Power Technology Research Institute Co.,Ltd.,Shenzhen 518031,China)

机构地区：[1]东北电力大学热流科学与核工程实验室,吉林吉林132012 [2]东北电力大学能源与动力工程学院,吉林吉林132012 [3]中广核研究院有限公司,广东深圳518031

出　　处：《原子能科学技术》2023年第2期264-275,共12页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12005036)。

摘　　要：花瓣形燃料元件具有换热性能强和无需定位格架等优点,能进一步提高反应堆的功率密度和经济性。为此,本文利用欧拉两流体模型,同时结合RPI壁面沸腾模型,对2×2花瓣形燃料元件棒束通道内过冷流动沸腾特性开展数值研究。通过圆管过冷沸腾实验数据验证了模型的准确性。开展了流速和热流密度参数对花瓣形燃料元件棒束通道内流动、换热及空泡份额分布影响的数值研究。结果表明,通道内冷却剂的流动速度分布不均匀;横向流动沿主流方向存在波动;空泡份额在燃料元件的内凹弧与外凸弧处表现出较大差异;同时,由于流场和换热形式的不同,导致燃料元件的周向壁面温度呈现不均匀分布,横向流动的存在影响着壁面热流分配情况。The petal-shape fuel elements have the advantages of strong heat transfer performance and no need for a spacer grid, allowing the reactor’s power density and economics to be increased even further. The Eulerian two-fluid model in combination with the RPI wall boiling model was used to investigate the boiling properties of the subcooled flow in the rod bundle channel of a 2×2 petal-shape fuel element in the paper. First, the accuracy of the interphase force model and the RPI closure model was evaluated using experimental data from subcooled boiling in a circular tube to accurately replicate two-phase flow heat transfer in the channel of the petal-shape fuel element. For the subcooled boiling phenomenon in the channel of a petal-shape fuel element rod bundle at pressure of 15.5 MPa, the numerical study of the effects of different flow velocities(1.4, 2 and 2.5 m/s) and heat flow flux(450, 650, and 800 kW/m~2) on the flow, heat transfer, and void fraction distribution in the channel was carried out. The results demonstrate that the coolant flow velocity in the channel is unevenly distributed, with the maximum flow velocity in the channel’s central region, and the fluid velocity on the windward side of the fuel element being greater than the leeward side. As the inlet flow velocity increases, the flow field on the leeward side(at Line2) becomes more nonuniform. The transverse flow in the channel is primarily found in the inner concave arc of the fuel element, and the intensity of the transverse flow varies with the distance of the adjacent fuel elements. Due to the uneven flow field, the subcooled boiling is more intense and the void fraction is larger in the inner concave arc region, while the void fraction exhibits a huge disparity between the inner concave arc and the outer convex arc of the fuel element. The void percent at the fuel element’s leeward side(15°, 110°, 195°, and 285°) is higher than the void fraction near the outer convex arc’s windward side(70°, 160°, 250°, and 340°). The temperatu

关 键 词：花瓣形燃料元件 过冷沸腾 RPI壁面沸腾模型 数值研究 

分 类 号：TL334[核科学技术—核技术及应用]