叶顶间隙结构对轴流铅铋泵叶轮磨损特性的影响  

Influence of impeller top clearance structure on the wear characteristics of the impeller of an axial flow lead-bismuth pump

作　　者：常杰元 黎义斌[1,2] 马文生 张人会[1,2] 刘欣 牛腾 CHANG Jieyuan;LI Yibin;MA Wensheng;ZHANG Renhui;LIU Xin;NIU Teng(School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Innovation Research Center of Nuclear Grade Pump Advanced Equipment of Lanzhou University of Technology,Lanzhou 730050,China;Chongqing Water Pump Factory Co.,Ltd.,Chongqing 400033,China)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]兰州理工大学核级泵先进装备创新研究中心,兰州730050 [3]重庆水泵厂有限责任公司,重庆400033

出　　处：《核技术》2023年第10期54-62,共9页Nuclear Techniques

基　　金：甘肃省教育厅"双一流"重点项目。

摘　　要：铅冷快堆反应回路中的高温液态铅铋金属会对轴流铅铋泵叶轮叶片头部产生冲刷磨损效应,造成叶片表面保护层破裂从而加快材料腐蚀速率。为了降低高温液态金属对叶片表面的冲刷磨损效应,设计平面、倒直角和倒圆角的三种叶顶间隙结构,并通过缩比换算方法验证仿真结果的可靠性,继而采用ANSYS CFX流体动力学软件分析了不同叶顶间隙结构下的流速、剪切力、流态随冲刷磨损特性变化规律,并利用壁面熵产率方法分析了高温液态铅铋金属在材料表面的能量损耗。结果表明:标准工况下倒直角模型的扬程和效率较平面分别降低了1.02%和0.64%,倒圆角模型扬程降低了0.51%,而效率提升了0.51%。叶轮内冲刷磨损效应主要发生在叶片轮缘进口边附近,倒直角和倒圆角设计可以通过降低叶顶间隙的流速和改善流态的途径减小叶片表面机械能损耗,从而降低该位置的冲刷磨损效应。因此倒圆角设计和倒直角设计能够改善高温液态铅铋金属对叶片头部冲刷磨损的影响。[Background]The high-temperature liquid lead-bismuth metal has a scouring and wear effect on the head of the axial flow lead-bismuth pump impeller blades in a lead-cooled fast reactor system,causing the protective layer on the blade surface to break down and material corrosion rate to accelerate.[Purpose]This study aims to reduce the scouring wear effect of the high temperature liquid metals on blade surfaces.[Methods]First of all,three types of leaf top clearance structures,i.e.,plane,chamfered right angle,and chamfered rounded angle,were designed.Then,the reliability of the simulation results was verified by the scaling conversion method,and the commercial CFD software ANSYS CFX with SST k-ωturbulence model was employed to analyze the variation of flow velocity,shear force,and flow pattern with scouring and wear characteristics under different leaf top clearance structures.Finally,the energy loss of the high temperature liquid lead-bismuth metal on the material surface was analyzed using the wall entropy yield.[Results]Analysis results show that the head and efficiency of the chamfered right angle model are reduced by 1.02%and 0.64%,respectively,compared with those of the flat surface under standard operating conditions,and the chamfered angle model shows a 0.51%reduction in the head and 0.51%efficiency increase.The impeller scouring wear effect occurs predominantly near the inlet edge of the blade rim,and the effect of the high temperature liquid metal on the blade head scouring wear is improved by the chamfered and rounded designs.[Conclusions]The chamfered and rounded designs reduces the mechanical energy loss on the blade surface by reducing the flow velocity at the top clearance and reducing the scouring wear effect at this location.Therefore,the rounded design and the right angle design could improve the influence of high-temperature liquid lead-bismuth metal on the erosion wear of the blade head.

关 键 词：轴流铅铋泵 叶顶间隙 冲刷磨损 数值模拟 

分 类 号：TL425[核科学技术—核技术及应用]