核电站冷凝泵首级叶轮与导流壳内流瞬态特性

为研究核电站冷凝泵首级叶轮与导流壳内流瞬态特性，建立叶轮与导流壳的水体模型并进行了数值模拟，得到不同工况下扬程波动的曲线、叶轮受到的径向力矢量分布以及设计工况下叶轮与导流壳内压力脉动的时域和频域特性。计算结果表明：大流量下的扬程振幅略高于小流量下的扬程振幅,当叶片出口掠经隔舌处时，扬程达到谷值，当叶片出口逐渐远离隔舌时，扬程达到峰值；从叶轮进口向叶轮出口压力脉动幅值递增；叶轮出口处，从叶片工作面向叶片背面压力脉动幅值递减，导流壳内部压力脉动主频接近叶频，导流壳隔舌附近的压力脉动振幅较大；叶轮在设计工况下径向力平均绝对值较小，且其指向大致与导流壳隔舌呈90°，当偏离设计工况时径向力产生明显的偏向。

Flow Transient Characteristic in the First Impeller and Diversion Shell of Condensate Pump in Nuclear Power Plant

In order to study the flow transient characteristic in the first impeller and diversion shell of the condensate pump in nuclear power plant, the water model of the first impeller and the diversion shell was established and simulated. The fluctuation curve of the head, the radial force vector distribution of the impeller under different working conditions and the time domain and frequency domain characteristics of the pressure pulsation in the impeller and the diversion shell under design condition were obtained. The results show that the amplitude of the head under the large flow condition is slightly higher than the amplitude of the head under the small flow condition, when the blade outlet is sweeping through the tongue, the head reaches the valley value, and when the blade outlet is gradually away from the tongue, the head increases and reaches the peak. The amplitude of the pressure pulsation from the inlet of the impeller to the outlet increases gradually. At the impeller outlet, the amplitude of the pressure pulsation decreases from the blade working surface to the blade back surface. The diversion shell pressure pulsation frequency is very close to blade frequency, and the pressure pulsation amplitude at the tongue is significantly larger than that at the other positions. The absolute value of the average radial force in design condition is less than that in other working conditions and radial force directs substantially 90° diversion of the tongue in design condition. When deviating from the design condition, the radial force produces an obvious bias.