Effect of medium viscosity on performance conversion of pump as turbine
YANG Junhu1,2, LEI Lei1, ZHANG Shuwei1, MIAO Senchun1,2, YAN Jun1
1. School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Key Laboratory of Fluid Machinery and Systems, Gansu Province, Lanzhou, Gansu 730050, China
Abstract:In order to study the variation characteristics of performance conversion factors of pump and turbine with viscosity and specific speed, centrifugal pumps with five different specific speeds were chosen as pump and turbine. The flows in the turbines were numerically simulated at five different viscosities. Based on simulated results, the mathematical relationships such as head-flow rate and efficiency-flow rate are obtained with curve fitting. Then the head, efficiency and flow rate are decided at the best efficiency point where the slope of the efficiency curve with respect to flow rate is zero. Eventually, flow rate, head and efficiency conversion factors are calculated based on the flow rate, head and efficiency are at a viscosity higher than water and those at the viscosity of water are at best efficiency points. It is shown that medium viscosity has a greater influence on turbine performance, particularly, the hydraulic efficiency of turbine decreases evidently with increasing viscosity. At the same specific speed, the conversion factors rise with increasing viscosity. At the same viscosity, the conversion factors reduce generally with increasing specific speed.
杨军虎,, 雷蕾, 张书玮, 苗森春,, 严俊. 介质黏度对泵作透平时性能换算的影响[J]. 排灌机械工程学报, 2017, 35(7): 553-557.
YANG Junhu,, LEI Lei, ZHANG Shuwei, MIAO Senchun,, YAN Jun. Effect of medium viscosity on performance conversion of pump as turbine. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(7): 553-557.
[1]KITTREDGE C P, THOMA D. Centrifugal pumps ope-rated under abnormal conditions[J]. Power, 1931, 73: 881-884.[2]袁亚飞. 基于离心泵的水力透平的流场分析及性能预测[D]. 兰州:兰州理工大学,2010.[3]周榕,唐晓晨,王辉,等. 离心泵作液力透平的数值模拟[J]. 化工机械,2013,40(5): 642-647. ZHOU Rong, TANG Xiaochen, WANG Hui, et al. Numerical simulation of centrifugal pump with turbine flow field[J]. Chemical machinery, 2013,40(5): 642-647.(in Chinese)[4]杨孙圣,李强,黄志攀,等. 不同比转数离心泵作透平研究[J]. 农业机械学报,2013, 44(3): 69-72. YANG Sunsheng, LI Qiang, HUANG Zhipan, et al. Research on different specific speed pumps used as turbines[J]. Transactions of the CSAM, 2013, 44(3): 69-72.(in Chinese)[5]STEPANOFF A J. Centrifugal and axial flow pumps[M]. New York: John Wiley & Sons.Inc., 1948.[6]SHARMA K R. Small hydroelectric projects-use of centrifugal pumps as turbines[R].Bangalore, India: Kirloskar Electric Co, 1985.[7]ALATORRE F C, THOMAS T H. The pumps-as-turbines(PATs)approach to small hydropower[C]//Proceedings of the 1st Wold Congress in Renewable Energy. UK: Pergamon Press, 1990: 4-8.[8]SCHMIEDL E. Serien-kreiselpumpen in turbinenbetrieb [M]. Pumpenagung,Germany: Karlsuhe, 1988.[9]CHILDS S M. Convert pumps to turbines and recover HP[J]. Hydrocarbon processing and petroleum refiner, 1962, 41(10): 173-174.[10]HANCOCK J W. Centrifugal pump or water turbine[J]. Pipe line news, 1963, 6: 25-27.[11]新滨 仁. 逆运转的水泵作为水轮机运行的研究[J]. 日本机械学会论文集(B编),2000(2): 72-77.[12]WILLIAMS A A. The turbine performance of centrifugal pumps: a comparison of prediction methods[J]. Journal of power and energy, 1994, 208(1): 59-66.[13]NAUTIYAL H, VARUN V, KUMAR A, et al. Experimental investigation of centrifugal pump working as turbine for small hydropower systems[J]. Energy science and technology, 2011, 1(1): 79-86.[14]SINGH P, NESTMANN F. A consolidated model for the turbine operation of centrifugal pumps[J]. Journal of engineering for gas turbines and power, 2011, 133(6): 063002.[15]杨孙圣. 离心泵作透平的理论分析数值计算与试验研究[D]. 镇江:江苏大学,2012.[16]SINGH P, NESTMANN F. An optimization routine on a prediction and selection model for the turbine operation of centrifugal pumps[J]. Experimental thermal and fluid science, 2010, 34(2): 152-164.[17]李文广. 黏度对离心泵作为水能回收液力透平使用的性能和流动影响的CFD研究[J]. 水泵技术,2014(3): 24-31. LI Wenguang. Effect of viscosity on turbine mode performance and flow of turbine by CFD method[J]. Pump technology, 2014(3): 24-31.(in Chinese)[18]史广泰, 杨军虎, 苗森春, 等. 不同进口截面下液力透平非定常压力脉动计算[J]. 航空动力学报, 2016, 31(3): 659-668. SHI Guangtai, YANG Junhu, MIAO Senchun, et al. Unsteady calculation of pressure pulsations within hydraulic turbine under different entrance sections[J]. Journal of aerospace power, 2016, 31(3): 659-668.(in Chinese)