Calculation and analysis of leakage of Francis pump-turbine
Min Zheng1, Liang Changping1, Dong Zhiqiang1, Liu Dianxing1, Qin Daqing2, Wei Xianzhu2
1.College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2.State Key laboratory of Hydropower Equipment, Harbin, Heilongjiang 150001, China
Abstract:In order to determine the leakage of Francis pump-turbine, the theoretical formula method was employed based on empirical parameters, and the CFD numerical simulation method using Navier-Stokes equations, RNG k-ε turbulence model and structured grid technology was used to calculate the leakage of a large reversible unit with the guide vane opening at 60%, 70%, 80% and 90%, and then a comparative analysis of the results of this two methods was done. The results show that the theoretical formula method involves the selection of empirical parameters, which leads a larger degree of dependence on computing experience, and has certain blindness and inaccuracy. When calculating the leakage under the turbine condition, the head of the points are equal, thus leading to that the leakage curve is a parallel straight line. It cannot reflect the real law between the leakage and the working conditions. By comparing the performance curves calculated by the CFD numerical simulation with the testing performance curves, the agreement of the results are better, verifying the accuracy of CFD numerical simulation and the feasibility of the clearance leakage calculation. It can describe the clearance flow more accurately and overcome the drawbacks of the theoretical method in calculation.
[1]梅祖彦. 抽水蓄能发电技术[M]. 北京:机械工业出版社,2000:1-10.[2]王焕茂,吴钢,吴伟章,等. 混流式水泵水轮机驼峰区数值模拟及分析[J]. 水力发电学报,2012,31(6):253-258. Wang Huanmao,Wu Gang,Wu Weizhang, et al. Numerical simulation and analysis of the hump district of Francis pump-turbine[J]. Journal of Hydroelectric Engineering,2012,31(6):253-258.(in Chinese)[3]刘锦涛,刘树红,孙跃昆,等. 水泵水轮机空载开度压力脉动特性预测[J]. 工程热物理学报,2012,33(3):411-414. Liu Jintao,Liu Shuhong,Sun Yuekun, et al. Prediction of pressure fluctuation of a pump-turbine at no-load opening[J]. Journal of Engineering Thermophysics,2012,33(3):411-414.(in Chinese)[4]张兰金,王正伟,常近时. 混流式水泵水轮机全特性曲线S形区流动特性[J]. 农业机械学报,2011,42(1):39-43. Zhang Lanjin,Wang Zhengwei,Chang Jinshi. Flow of pump-turbine on S-shaped region of complete characteri-stics[J]. Transactions of the Chinese Society for Agricultural Machinery,2011,42(1):39-43.(in Chinese)[5]刘竹青,孙卉,肖若富,等. 水泵水轮机“S”特性及性能改善[J]. 水力发电学报,2013,32(2):257-260. Liu Zhuqing,Sun Hui,Xiao Ruofu, et al. S-shaped characteristics of pump-turbine and improvement on its performance[J]. Journal of Hydroelectric Engineering,2013,32(2):257-260.(in Chinese)[6]肖若富,孙卉,杨魏,等. 水泵水轮机预开导叶的优化分析[J]. 排灌机械工程学报,2013,31(2):128-131. Xiao Ruofu,Sun Hui,Yang Wei,et al. Optimization of misaligned guide vanes scheme of pump-turbine[J]. Journal of Drainage and Irrigation Machinery Enginee-ring,2013,31(2):128-131.(in Chinese)[7]纪兴英,赖旭. 低比转速水泵水轮机“S”区特性数值模拟[J]. 水动力学研究与进展,2011,26(3):318-325. Ji Xingying,Lai Xu. Numerical simulation of the S-shaped characteristics of the pump-turbine[J]. Chinese Journal of Hydrodynamics,2011,26(3):318-325.(in Chinese)[8]尹俊连,刘锦涛,王乐勤,等. 水泵水轮机泵工况小流量区压力脉动预测[J]. 工程热物理学报,2011,32(7):1141-1144. Yin Junlian,Liu Jintao,Wang Leqin,et al. Prediction of pressure fluctuations pump turbine under off-design condition in pump mode[J]. Journal of Engineering Thermophysics,2011,32(7):1141-1144.(in Chinese)[9]Tong Seop Kim,Kyu Sang Cha. Comparative analysis of the influence of labyrinth seal configuration on leakage behavior [J]. Journal of Mechanical Science and Technology,2009,23(10):2830-2838.[10]Jeffrey J, MooreJ J. Three-dimensional CFD rotor dynamic analysis of gas labyrinth seals[J]. Journal of Vibration and Acoustics,2003,125:427-433.[11]Wang Weizhe,Liu Yingzheng,Jiang Puning,et al. Numerical analysis of leakage flow through two labyrinth seals [J]. Journal of Hydrodynamics: Ser B,2007,19(1):107-112.[12]关醒凡. 现代泵理论与设计[M]. 北京:中国宇航出版社,2011:564-619.[13]沙波夫 H M. 水电站的水轮机设备[M]. 黄明忠,徐纪方,译.北京:中国工业出版社,1964.[14]Yakhot V, Orzag S A. Renormalization group analysis of turbulence: Basic theory[J]. Journal of Scientific Computing,1986,1(1):3-11.