高水头电站水轮机沙水流动特性的数值研究

研究泥沙磨损有助于降低水轮机磨损,延长水轮机使用寿命。运用Partical两相流模型对高水头多泥沙电站的水轮机全流道内部沙水两相流动进行数值计算,并分别分析转轮进口沿叶高20%、50%、80%流面的流动特性。计算结果表明,压力从固定导叶进口到转轮出口圆周方向的周向性较好,分布合理,最低压力高于空化压力。活动导叶上泥沙相体积分数最高在导叶头部位置,尾部泥沙相体积分数也较高,导叶靠近头部处和导叶尾部泥沙速度最大。转轮叶片各叶高流面泥沙相体积分数均在叶片工作面尾部达到最大,叶片头部和尾部位置泥沙速度均较高。研究结果对水轮机选材、关键磨损部位的预测及防护方案具有指导意义。

Numerical Study on Sand Flow Characteristics of Turbine at High Head Hydropower Station

Studying sediment wear helps reduce turbine wear and extend turbine life. Two phase flow model of Partical was used to numerically calculate two-phase flow in the whole flow passage of a high head and sediment power plant. The flow characteristics of the 20%, 50% and 80% flow surfaces along the runner inlet were analyzed respectively. The results show that the circumferential direction of the pressure from the inlet of the fixed guide blade to the circumferential direction of the runner outlet is better, the distribution is reasonable, and the minimum pressure is higher than the cavitation pressure. The volume fraction of sediment phase on the movable guide vane is the highest in the position of the guide vane head, and the volume fraction of the sediment phase in the tail is also higher. The sediment velocity near the guide vane and the guide vane is the largest. The volume fraction of the sediment in the high flow surface of the blade of the runner blade reached the maximum at the end of the blade surface, and the velocity of the sediment in the head and tail of the blade was higher. The results are of guiding significance to the selection of hydraulic turbine, the prediction of key wear parts and the protection scheme.