叶轮几何参数优化对核主泵惰转特性的影响

为了研究核主泵叶轮部分几何参数对核主泵惰转特性的影响,首先对核主泵不同阶段惰转特性及影响惰转特性的因素进行分析.然后基于泵外特性的建模方法建立模型核主泵的动态仿真模型,并且通过研究不同叶轮几何参数下的惰转模拟方案,分析得到更优设计方案.结果表明:惰转性能的影响主要体现在惰转过渡过程的非线性惰转瞬变阶段.在一定范围内,包角越大对应泵的惰转性能越优;叶轮叶片数越少,对应泵的惰转性能越优;随着叶轮进口边向出口延伸,对应泵惰转性能越优.通过优化核主泵叶轮结构,可以得到惰转特性更优的设计:选择120°包角、进口边位置为方案b,叶轮叶片数为5.优化后的主泵惰转流量曲线达到半流量的时间比优化前对应的曲线晚0. 07T,即0. 91 s.当泵保持其他设计参数不变,只是改变几何参数来优化惰转性能时,其对应的功率曲线越低,则其惰转特性越好.

Influence of optimization of impeller geometric parameters on coast-down performance of nuclear reactor coolant pump

In order to investigate the influence of impeller import edge position,number of impeller blades and impeller wrap angle on coast-down performance of the nuclear reactor coolant pump,the dynamic simulation model of the the pump cost-down process of the nuclear reactor coolant pump model through the modeling method was established based on the characteristics of the pump. After the test was verified,the correct simulation program was finally established. Then by defining the head and torque curve simulation under different geometric parameters,the idle performance curve of the core pump was obtained under different conditions,and the better design situation was obtained. The results show that the effect of coast-down performance is mainly reflected in the nonlinear idle transition of the coast-down transition process. The larger the wrap angle,the better the coast-down performance of the pump,The smaller the number of impeller blades in a certain range,the better the coast-down performance. As the inlet side of the impeller extends forward,the corresponding pump has better coastdown performance: the 120° wrap angle and the inlet side position are selected as the b plan,and the number of impeller blades is 5. The optimized nuclear reactor coolant pump idle flow curve reaches the half flow time 0. 07 T or 0. 91 s later than the corresponding curve before optimization. When the pump keeps other design parameters unchanged,and just changing geometric parameter to optimize the coastdown performance,the lower the power curve corresponding to it,the better its coast-down performance.