核电站冷却剂泵惰转过程水力部件内部能量转换研究

Study on Energy Conversion of Hydraulic Components During Idle Process of Coolant Pump in Nuclear Power Station

为了探索核电站一回路冷却剂泵进入惰转状态后,泵中各水力部件的能量转换特性,采用数值方法对某台冷却剂泵的惰转状态进行了研究。结果表明:随着惰转时间的增加,各水力过流部件的扬程损失经过10 s后降低至50%以下;惰转过程中进口段动压扬程从6.8 m急速下降至0 m,静压扬程在140 s后从-7 m升高至0 m;惰转开始后叶轮出口的静压能缓慢降低,而其进口静压能快速增加;随着惰转时间的增加,叶轮静压扬程比动压扬程下降得快,导叶与叶轮的动压能变化规律相反;蜗壳进出口的动压能随惰转时间的增加急速下降,蜗壳进口的静压能从惰转开始迅速下降。惰转开始时,24.33 m以上的动压能主要分布于叶轮出口、导叶进口和蜗壳的出口处;在t=110 s时大部分区域动压能在12.17 m以下;在t=200 s时,动压能主要分布在0~6.08 m;蜗壳内较大的静压能分布区域范围逐渐减小。

In order to explore the energy conversion characteristics of the hydraulic components in the coolant pump after entering idling state, numerical method was used to study the idling state of the coolant pump. Results show that with the increase of idle time, the head loss of each hydraulic flow component decrease to less than 50% after 10 s. During the idling process, the dynamic pressure head of the inlet section decrease sharply from 6.8 m to 0 m, and the static pressure head increase from-7 m to 0 m after 140 s. At the beginning of idling, the static pressure energy at the outlet of the impeller decrease slowly, which increase rapidly at the inlet. With the increase of idle time, the static pressure head of impeller decrease faster than the dynamic pressure head, the dynamic pressure energy of guide vane and impeller change in a contrary way. The dynamic pressure energy at the inlet and outlet of the volute decrease rapidly with the increase of idle time, and the static pressure energy at the inlet of the volute decrease rapidly from idling. At the beginning of idling, the dynamic pressure energy above 24.33 m is mainly distributed at the outlet of impeller, guide vane inlet and the outlet of volute;When t=110 s, the dynamic pressure energy in most areas is mainly below 12.17 m;When t=200 s, the dynamic pressure energy is mainly distributed in 0-6.08 m. The distribution area of large static pressure energy in the volute decrease gradually.