Abstract: In order to predict the flow distribution between the upper and lower branches of the internal cooling circuit within a canned motor reactor coolant pump（RCP）， the stator can deformations and the influences on axial resistance of the annular gap flow were studied. The deformed profile of stator cans under the high pressure was calculated with the finite element method and verified by experiments. The influences of stator can deformations on annular gap flow were studied by using computational fluid dynamics and a modified model for axial flow resistance evaluation was established by variable parameter analysis and mathematical fitting. Calculation result from the established model shows that, compared to ideal cylindrical state, 11% boundary deformation of the stator can under the rated working state of the RCP, will lead to 83% decrease of the axial flow pressure drop in the rotor and stator clearance.

Key words: reactor coolant pump（RCP）, canned motor, deformation of stator can, annular gap flow, axial flow resistance

摘要： 针对核主泵屏蔽电机中内冷回路上下支路流量分配的预测问题，研究了屏蔽电机定子屏蔽套变形规律及其对间隙环流轴向流阻的影响规律。采用有限元方法计算了内冷介质高压作用下定子屏蔽套轮廓的圆角沟槽状变形特征，并进行了实验验证。采用计算流体动力学方法研究了界面非圆轮廓形变对间隙流场的影响，通过变参数分析与数学拟合，建立了核主泵屏蔽电机定子屏蔽套形变后的间隙环流轴向流动阻力系数修正模型。该模型的计算结果表明，在屏蔽式核主泵的额定工作状态，驱动电机定子界面轮廓相较于理想状态存在11%的变形，这种变形会导致电机定转子间隙流动轴向沿程压降值下降到无形变间隙的83%左右。

关键词: 核主泵, 屏蔽电机, 定子屏蔽套变形, 间隙环流, 轴向流阻