Hydraulic performance prediction of a prototype four-nozzle Pelton turbine by entire flow path simulation
Hydraulic performance prediction of a prototype four-nozzle Pelton turbine by entire flow path simulation
复制标题
通过全流路模拟预测四喷嘴冲击式水轮机原型的水力性能
DOI：
10.1016/j.renene.2018.02.075
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发表时间：
2018
期刊：
影响因子：
8.7
通讯作者：
Ahn Soo-Hwang
中科院分区：
文献类型：
--
作者：
Zeng Chongji;Xiao Yexiang;Luo Yongyao;Zhang Jin;Wang Zhengwei;Fan Honggang;Ahn Soo-Hwang
本文对一台四喷嘴冲击式涡轮机样机在三种水头下的全流道进行了数值模拟，从管道流动到喷嘴射流在动叶上形成的水膜流动，再到从动叶边缘滴落到空中。采用三维瞬态气水两相流数值模拟方法，对冲击式涡轮机内不同类型的流动进行了分析。对静止部件和旋转转轮的水力性能进行了沿着全流道的评价，流动分析表明，静止部件内的压力脉动很小，水流可视为稳定流动。由于摩擦损失的减少，这些部分的水力损失随着水头的增加而下降。然后，讨论了旋转转轮内射流与水斗的相互作用。反弧段表面的压力脉动随水膜流的扩展而脉动，并消耗10%~ 25%的水能。挑坎的水力性能在最佳水头处最高，随着水头的变化而降低。非定常流分析表明，如果水头或两个射流之间的角度减小，则两个相邻射流之间存在干扰的可能性。
This paper presents entire flow path simulations in a prototype four-nozzle Pelton turbine under three water heads, from pipe flow to nozzle jet water sheet flow on rotating bucket and drop from bucket brim on the air. Different type flows in the Pelton turbine are analyzed by adopting the three-dimensional transient air-water two-phase flow simulation method. Hydraulic performance of stationary parts and rotating runner are evaluated along the entire flow path. Flow analyses indicate that the pressure pulsation is very low and the water flow could be regarded as steady flow in the stationary parts. The hydraulic loss in these parts drops as the water head increases due to a reduction of the frictional loss. Afterwards, the interactions between the jets and buckets in the rotating runner are discussed. The pressure pulse on the bucket surface pulsates with the spreading of the water sheet flow and takes up 10%–25% water energy. The hydraulic performance of the bucket is highest at optimal water head and decreases as the water head varies. Unsteady flow analyses show that there is a potential for interference between the two adjacent jets if the water head or the angle between the two jets decreases.