Three-dimensional simulation of unsteady flows in a pump-turbine during start-up transient up to speed no-load condition in generating mode
Three-dimensional simulation of unsteady flows in a pump-turbine during start-up transient up to speed no-load condition in generating mode
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水泵水轮机在发电模式下从启动瞬态到加速空载条件期间的非定常流动的三维模拟
DOI：
10.1177/0957650916646911
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发表时间：
2016-05
影响因子：
1.7
通讯作者：
Yao, Ze
中科院分区：
文献类型：
--
作者：
Li, Zhongjie;Bi, Huili;Wang, Zhengwei;Yao, Ze
采用三维数值模拟方法对某水泵水轮机启动过程的瞬态特性和流动特性进行了研究。采用液力耦合方法，得到了随转轮转矩和转动系统惯性变化的转速。采用动态嵌套网格技术对导叶运动进行了数值模拟，并保证了网格质量。通过与已有的试验结果的比较，验证了本文方法在预测水泵水轮机启动瞬态特性方面的有效性，具有较好的精度。在启动瞬态过程中，导叶按照规定的顺序打开，这会增加装置的流速。由于施加在转轮叶片上的水力能量的增加，转轮加速。当接近速度空载条件时，发现缠绕整个无叶空间的环形流动，即我们称之为“水环”，阻塞了沿着圆周的通流，并且水泵水轮机的特征在于转轮中的突出部分泵流状态，其使扭矩与空载相等。因此，转轮旋转速度停止增加并稳定在额定速度附近。预测结果表明，转速空载时的压力波动幅度可达满载时的3.8 ~ 8倍，转速空载时的不稳定性明显增强。
Three-dimensional numerical simulation for a prototype pump-turbine has been performed to investigate the transient characteristics and flow behaviors in the startup process. The rotational speed, which varies with runner torque and inertial of the rotating systems, is obtained by hydraulic-force coupling method. To simulate the guide vane motions, dynamic overset mesh technique is applied with good maintenance of mesh quality. Comparisons with the existing experimental results verify the validity of the current method in predicting the startup transient characteristics of a pump-turbine with good accuracy. During the startup transient, the guide vanes open according to a prescribed sequence, which brings in increasing flow rate to the unit. The runner accelerates due to growing water power energy exerted on the runner blades. When approaching the speed no-load condition, a ring-shaped flow enlacing the entire vaneless space, that we term “water-ring,” is found to block the through-flow along the circumference, and the pump-turbine features a prominent partial pump flow state in the runner, which equalizes the torque to no load. Thus, the runner rotational speed stops increasing and stabilizes toward rated speed. The prediction shows that the pressure fluctuation amplitude of the speed no-load can be 3.8 to 8 times that of the full load, presenting evidently stronger instability at the speed no-load.
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DOI：
10.1088/1755-1315/22/3/032049
发表时间：
2014-03
期刊：
IOP Conference Series: Earth and Environmental Science
影响因子：
--
作者：
Z. Li;Z. W. Wang;H. Bi
通讯作者：
Z. Li;Z. W. Wang;H. Bi
DOI：
10.1115/fedsm2003-45249
发表时间：
2003
期刊：
--
影响因子：
--
作者：
A. Ruprecht;Thomas Helmrich
通讯作者：
A. Ruprecht;Thomas Helmrich
DOI：
10.15480/882.231
发表时间：
2006
期刊：
--
影响因子：
--
作者：
Hidajet Hadžić
通讯作者：
Hidajet Hadžić
DOI：
--
发表时间：
2005
期刊：
--
影响因子：
--
作者：
H. Huth
通讯作者：
H. Huth
影响因子：
8.7
作者：
J. Anagnostopoulos;D. Papantonis
通讯作者：
J. Anagnostopoulos;D. Papantonis