Dynamic measurements on unsteady pressure pulsations and flow distributions in a nuclear reactor coolant pump
Dynamic measurements on unsteady pressure pulsations and flow distributions in a nuclear reactor coolant pump
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DOI：
10.1016/j.energy.2020.117305
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发表时间：
2020-05
期刊：
影响因子：
9
通讯作者：
Dan Ni;Ning Zhang;B. Gao;Z. Li;Minguan Yang
中科院分区：
文献类型：
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作者：
Dan Ni;Ning Zhang;B. Gao;Z. Li;Minguan Yang
核反应堆冷却剂泵（RCP）的运行稳定性将直接影响核电站的安全运行。全面分析反应堆内部流动结构的动态特性，对评价反应堆的运行稳定性至关重要。由于反应堆球形壳壁的非定常压力特性和反应堆内部的动态流场比较复杂，因此采用可靠的方法对其进行精确测量具有很高的要求。本文对不同工况下的反应堆球形壳壁和内部流动进行了动态压力脉动和激光多普勒测速（LDV）测量。通过对压力脉动的测量，认为不同的非定常流动结构直接影响压力脉动特性，从而产生不同的激励信号。转子-定子相互作用（RSI）与扩压器排出的流体与循环流碰撞到机匣底部的相互耦合是导致强压力脉动的主要原因。动态LDV测量结果表明，扩压器叶片尾缘存在明显的逆时针方向的周期性涡脱落，特别是在大流量（1.2QN）下，这也是导致叶片速度脉动强烈的主要原因。本文的核心是通过多种动态测量方法的结合，对复杂水力机械内部的动态流动特性进行综合阐述。此外，对动态流动特性的详尽了解是优化RCP的基础。实验结果可为具有稳定运行特性的RCP的优化设计提供思路和依据。
The operational stability of the nuclear reactor coolant pump (RCP) will directly affect the safety of the nuclear power plants (NPPs). A comprehensive analysis of the dynamic characteristics of the internal flow structure in the RCP is extremely important to assess its operational stability. Because the unsteady pressure characteristics of the spherical casing wall of the RCP and the dynamic flow field inside the RCP are complicated, it is highly demanding to be accurately measured by a reliable approach. Dynamic pressure pulsation and Laser Doppler Velocimetry (LDV) measurements have been carried out on the spherical casing wall and internal flow of the RCP under different operating conditions. Based on the pressure pulsation measurement, it is convinced that different unsteadiness flow structures directly affect the pressure pulsation characteristics, which will generate various excitation signals. The intercoupling between rotor-stator interaction (RSI) and the collision of the fluid discharged from the diffuser with the circulating flow to the casing bottom is the main reason for leading to strong pressure pulsations. Dynamic LDV measurement result shows that there is a significant counterclockwise periodic vortex shedding from the diffuser blade trailing edge, especially under high flow rate (1.2QN), which is also the main reason of strong velocity pulsations. The core of this paper is to comprehensively elaborate the dynamic flow characteristics in such a complex hydraulic machinery through combining multiple dynamic measurement methods. Moreover, an exhaustive understanding of dynamic flow characteristics is the basis for optimizing the RCP. The experimental results can provide ideas and basis for the optimization of the RCP with stable operation characteristics.