快堆二回路钠泵空化性能预测与分析

Prediction and Analysis of Cavitation Performance of Two Loop Sodium Pump for Fast Reactor

快堆二回路钠泵的空化性能是影响四代核电安全运行的关键因素。为确定不同工况下,预测快堆二回路钠泵空化性能更准确的空化模型,并为其空化性能的提升提供重要参考,采用RNGk-ε湍流模型及Zwart-Gerber-Belamri和Schnerr&Sauer空化模型,对0.3qd^1.2qd流量范围内的5个工况点进行非定常数值计算,分析不同工况下更准确的空化模型对应的内流场。结果表明:扬程突降前,设计工况和大流量工况,扬程计算值大于试验值,小流量工况相反,设计工况误差最小。随着流量增大,临界空化余量先减小后增大;扬程与临界空化余量的预测值:设计工况附近,Schnerr&Sauer空化模型更接近试验值,远离设计工况时,Zwart-Gerber-Belamri空化模型更接近试验值。空化域越靠近叶轮出口,对流场参数影响越大;空化发生在叶片工作面,扩散速度比发生在背面大的多;流量越大,空化对流场参数的影响越大。

Cavitation performance of two loop sodium pump for fast reactor is the key factor that affects security of fourth generation nuclear power.For predicting more accurate cavitation model of cavitation performance of two loop sodium pump for fast reactor under different conditions and offer important references,use RNGk-εturbulence model and Zwart-Gerber-Belamri Schnerr Sauer cavitation model to conduct unsteady numerical calculation for 5 working points in the range of 0.3 qd-1.2 qd,and analyze more accurate internal flow-field corresponded by cavitation model under different conditions.The result showed that before sudden drop of lift,design working condition and big flow condition,the calculated lift value is bigger than the experimental,while on the contrary for small flow,the designed working condition error is minimum.With flow increasing,critical remain cavitation first degrease and then increase;predicting value of lift and critical remain cavitation：near designed working condition,Schnerr Sauer cavitation model is nearer to experimental value,when being far from designed working condition,Zwart-Gerber-Belamri cavitation model is nearer to experimental value.More that cavitation is near to impeller exit,more that affects flow parameter;cavitation occurs in blade surface,diffusion rate is higher than the back;more the flow,more cavitation affecting flow parameter.