核主泵启动过程压力脉动和径向力研究

Study on Pressure Fluctuation and Radial Force during Startup of Reactor Coolant Pump

为研究核主泵启动过程中压力脉动和径向力的变化规律,根据AP1000启动过程的物性变化规律及参数设置,采用统计学方法对泵内无量纲压力脉动强度进行描述,采用频谱法分析了叶轮径向力。结果表明:导叶流道的压力脉动强度明显强于叶轮流道,随工作温度升高,强度递减;叶轮和压水室的压力脉动强度较弱,随工作温度升高,呈现不规律变化;叶轮径向力在叶频的1倍频和2倍频的脉动幅值较小,随工作温度升高,呈现不规律变化;而叶轮径向力在5倍频的脉动幅值最大,且随工作温度升高,其值递减;核主泵偏离设计工作点运行于常温下会导致导叶流道压力脉动增强,导致主泵的径向振动增强。

In order to explore the characteristics of the pressure fluctuation and the radial force during the startup of AP1000 reactor coolant pump, different numerical simulation schemes were carried out with the reactor coolant pump hydraulic model according the property changes and the parameters setting of AP1000 startup. Statistical method and spectral method were adopted to analyze the dimensionless pressure fluctuation intensity and radial force separately. The results show that the pressure fluctuation intensity of the guide vanes channel are stronger than that of the impeller channel and weaken as the temperature increases. The pressure fluctuation intensity of the impeller channel and pump case are weaker and change irregularly as the temperature increases. The amplitude of radial force fluctuation at blade frequency and twice blade frequency are weaker and change irregularly as the temperature increases. The amplitude of radial force fluctuation at five times blade frequency is the strongest and weakens as the temperature increases. Therefore when the reactor coolant pump runs at the temperature below the design operation temperature, it will cause the enhancement of pressure fluctuation intensity in guide vanes, which may enhance the radial vibration of reactor coolant pump.