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Research Papers: Flows in Complex Systems

Energy Analysis in a Pump-Turbine During the Load Rejection Process

[+] Author and Article Information
Xiaolong Fu

School of Energy Science and Engineering,
Harbin Institute of Technology,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: fuxiaolonghit@163.com

Deyou Li

School of Energy Science and Engineering,
Harbin Institute of Technology,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: lideyou@hit.edu.cn

Hongjie Wang

Professor
School of Energy Science and Engineering,
Harbin Institute of Technology,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: wanghongjie@hit.edu.cn

Guanghui Zhang

School of Energy Science and Engineering,
Harbin Institute of Technology,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: zhanggh@hit.edu.cn

Zhenggui Li

Key Laboratory of Fluid and Power Machinery
(Xihua University),
Ministry of Education Sichuan,
Chengdu 610039, China
e-mail: lzhgui@mail.xhu.edu.cn

Xianzhu Wei

State Key Laboratory of Hydro-Power Equipment,
Harbin Institute of Large Electrical Machinery,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: weixianzhu@hit.edu.cn

Daqing Qin

State Key Laboratory of Hydro-Power Equipment,
Harbin Institute of Large Electrical Machinery,
92 West Dazhi Street,
Nan Gang District,
Harbin 150001, China
e-mail: qindq@hec-china.com

1The authors contribute equally to the paper.

2Corresponding authors.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received September 5, 2017; final manuscript received April 15, 2018; published online May 18, 2018. Assoc. Editor: Wayne Strasser.

J. Fluids Eng 140(10), 101107 (May 18, 2018) (12 pages) Paper No: FE-17-1563; doi: 10.1115/1.4040038 History: Received September 05, 2017; Revised April 15, 2018

Complex energy conversion and energy dissipation occur in pump-turbines during the load rejection process. However, the underlying fluid mechanism is not clear. In order to solve these problems, in this study, a three-dimensional (3D) transient turbulent flow in a pump-turbine, with clearance during the load rejection process, was simulated using the method of coupling of the rigid rotor motion with flow and dynamic mesh technology. The simulated rotational speed shows good agreement with the experimental data. Most of the differences of rotational speed between simulations and experiments are very small and lower than 5%. Based on the numerical simulation, the energy conversion process, loss distribution, and flow mechanism in a pump-turbine were analyzed using the method of coupling of the entropy production analysis with the flow analysis. The results indicate that the load rejection process of a pump-turbine is an energy-dissipation process where the energy is converted among various energy forms. After load rejection, the hydraulic loss in the reverse pump process distributes primarily in the stay/guide vanes (GV), the vaneless space, and near draft tube inlet. While the hydraulic losses in the runaway process and the braking process are distributed mainly in the elbow section of the draft tube, the clearance of runner (RN), and the vaneless space, the hydraulic losses are mainly caused by viscous dissipation effects of the vortex flows, including the flow separation vortices, the shedding vortices of flow wake, the secondary flow, and the backflow.

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References

Zhang, Y. N. , Zhang, Y. N. , and Wu, Y. L. , 2016, “ A Review of Rotating Stall in Reversible Pump Turbine,” Proc. Inst. Mech. Eng., Part C, 231(7), pp. 1181–1204. [CrossRef]
Li, D. Y. , Wang, H. J. , Xiang, G. M. , Gong, R. Z. , Wei, X. Z. , and Liu, Z. S. , 2015, “ Unsteady Simulation and Analysis for Hump Characteristics of a Pump Turbine Model,” Renewable Energy, 77, pp. 32–42. [CrossRef]
Li, D. Y. , Gong, R. Z. , Wang, H. J. , Wei, X. Z. , Liu, Z. S. , and Qin, D. Q. , 2015, “ Numerical Investigation on Transient Flow of a High Head Low Specific Speed Pump-Turbine in Pump Mode,” J. Renewable Sustainable Energy, 7(6), p. 063111.
Li, D. Y. , Gong, R. Z. , Wang, H. J. , Xiang, G. M. , Wei, X. Z. , and Liu, Z. S. , 2015, “ Dynamic Analysis on Pressure Fluctuation in Vaneless Region of a Pump Turbine,” Sci. China Technol. Sci., 58(5), pp. 813–824. [CrossRef]
Walseth, E. , Nielsen, T. , and Svingen, B. , 2016, “ Measuring the Dynamic Characteristics of a Low Specific Speed Pump-Turbine Model,” Energies, 9(3), p. 199. [CrossRef]
Côté, P. , Dumas, G. , Moisan, É. , and Boutetblais, G. , 2014, “ Numerical Investigation of the Flow Behavior Into a Francis Runner During Load Rejection,” IOP Conf. Ser.: Earth Environ. Sci., 22(3), p. 032023. [CrossRef]
Hosseinimanesh, H. , Vu, T. C. , Devals, C. , Nennemann, B. , and Guibault, F. , 2014, “ A Steady-State Simulation Methodology for Predicting Runaway Speed in Francis Turbines,” IOP Conf. Ser.: Earth Environ. Sci., 22(3), p. 032027. [CrossRef]
Fortin, M. , Houde, S. , and Deschênes, C. , 2014, “ Validation of Simulation Strategies for the Flow in a Model Propeller Turbine During a Runaway Event,” IOP Conf. Ser.: Earth Environ. Sci., 22(3), p. 032026. [CrossRef]
Liu, J. T. , 2011, “ Numerical Simulation of the Transient Flow in a Radial Flow Pump During Stopping Period,” ASME J. Fluids Eng., 133(11), p. 111101. [CrossRef]
Liu, J. T. , Liu, S. H. , Sun, Y. K. , Jiao, L. , Wu, Y. L. , and Wang, L. Q. , 2013, “ Three-Dimensional Flow Simulation of Transient Power Interruption Process of a Prototype Pump-Turbine at Pump Mode,” J. Mech. Sci. Technol., 27(5), pp. 1305–1312. [CrossRef]
Zhang, X. X. , Cheng, Y. G. , Xia, L. S. , Yang, J. D. , and Qian, Z. D. , 2016, “ Looping Dynamic Characteristics of a Pump-Turbine in the S-Shaped Region During Runaway,” ASME J. Fluids Eng., 138(9), p. 091102. [CrossRef]
Amiri, K. , Mulu, B. , Raisee, M. , and Cervantes, M. J. , 2016, “ Unsteady Pressure Measurements on the Runner of a Kaplan Turbine During Load Acceptance and Load Rejection,” J. Hydraul. Res., 54(1), pp. 56–73. [CrossRef]
Zhang, Y. N. , Chen, T. , Li, J. W. , and Yu, J. X. , 2017, “ Experimental Study of Load Variations on Pressure Fluctuations in a Prototype Reversible Pump Turbine in Generating Mode,” ASME J. Fluids Eng., 139(7), p. 074501. [CrossRef]
Trivedi, C. , Cervantes, M. J. , Gandhi, B. K. , and Dahlhaug, O. G. , 2014, “ Transient Pressure Measurements on a High Head Model Francis Turbine During Emergency Shutdown, Total Load Rejection, and Runaway,” ASME J. Fluids Eng., 136(12), p. 121107.
Trivedi, C. , Gandhi, B. , and Michel, C. J. , 2013, “ Effect of Transients on Francis Turbine Runner Life: A Review,” J. Hydraul. Res., 51(2), pp. 121–132. [CrossRef]
Casartelli, E. , Mangani, L. , Romanelli, G. , and Staubli, T. , 2014, “ Transient Simulation of Speed-No Load Conditions With an Open-Source Based C++ Code,” IOP Conf. Ser.: Earth Environ. Sci., 22(3), p. 32029. [CrossRef]
Hosseinimanesh, H. , Devals, C. , Nennemann, B. , Reggio, M. , and Guibault, F. , 2017, “ A Numerical Study of Francis Turbine Operation at No-Load Condition,” ASME J. Fluids Eng., 139(1), p. 011104. [CrossRef]
Nennemann, B. , Morissette, J. F. , Chamberlandlauzon, J. , Monette, C. , Braun, O. , Melot, M. , Coutu, A. , Nicolle, J. , and Giroux, A. M. , 2014, “ Challenges in Dynamic Pressure and Stress Predictions at No-Load Operation in Hydraulic Turbines,” IOP Conf. Ser.: Earth Environ. Sci., 22(3), p. 032055. [CrossRef]
Gong, R. Z. , Wang, H. J. , Chen, L. X. , Li, D. Y. , Zhang, H. C. , and Wei, X. Z. , 2013, “ Application of Entropy Production Theory to Hydro-Turbine Hydraulic Analysis,” Sci. China Technol. Sci., 56(7), pp. 1636–1643. [CrossRef]
Li, D. Y. , Gong, R. Z. , Wang, H. J. , Xiang, G. M. , Wei, X. Z. , and Qin, D. Q. , 2016, “ Entropy Production Analysis for Hump Characteristics of a Pump Turbine Model,” Chin. J. Mech. Eng., 29(4), pp. 803–812. [CrossRef]
Li, D. Y. , Wang, H. J. , Qin, Y. L. , Wei, X. Z. , and Qin, D. Q. , 2018, “ Numerical Simulation of Hysteresis Characterisitc in the Hump Region of a Pump-Turbine Model,” Renewable Energy, 115, pp. 433–447. [CrossRef]
Li, D. Y. , Wang, H. J. , Qin, Y. L. , Han, L. , Wei, X. Z. , and Qin, D. Q. , 2017, “ Entropy Production Analysis of Hysteresis Characteristic of a Pump-Turbine Model,” Energy Convers. Manage., 149, pp. 175–191. [CrossRef]
Dhakal, T. P. , Walters, D. K. , and Strasser, W. , 2014, “ Numerical Study of Gas-Cyclone Airflow: An Investigation of Turbulence Modelling Approaches,” Int. J. Comput. Fluid Dyn., 28(1–2), pp. 1–15. [CrossRef]
ANSYS, 2012, ANSYS FLUENT 14.5 Theory Guide, ANSYS, Inc., Canonsburg, PA, pp. 724–746.
Zhang, L. , and Zhou, D. , 2013, “ CFD Research on Runaway Transient of Pumped Storage Power Station Caused by Pumping Power Failure,” IOP Conf. Ser.: Mater. Sci. Eng., 52(5), p. 52027. [CrossRef]
Strasser, W. , 2007, “ CFD Investigation of Gear Pump Mixing Using Deforming/Agglomerating Mesh,” ASME J. Fluids Eng., 129(4), pp. 476–484. [CrossRef]
Zhang, Y. N. , Liu, K. H. , Xian, H. Z. , and Du, X. Z. , 2017, “ A Review of Methods for Vortex Identification in Hydroturbines,” Renewable Sustainable Energy Rev., 81(Pt. 1), pp. 1269–1285.
Li, D. Y. , Han, L. , Wang, H. J. , Gong, R. Z. , Wei, X. Z. , and Qin, D. Q. , 2017, “ Flow Characteristics Prediction in Pump Mode of a Pump Turbine Using Large Eddy Simulation,” Arch. Proc. Inst. Mech. Eng. Part E, 231(5), pp. 961–977. [CrossRef]

Figures

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Fig. 1

The key component parts and 3D model of the pump-turbine

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Fig. 2

Schematic diagram of clearances between the RN and the stationary parts and relative spanwise height

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Fig. 3

Grids in key parts and y+ on the solid walls in boundary layers: (a) grids in key parts and (b) y+ on the solid walls

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Fig. 4

Mesh independency verification (discharge)

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Fig. 5

Unsteady total pressure experimental datum at the SC inlet

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Fig. 6

Unsteady static pressure experimental datum at the draft tube outlet

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Fig. 7

Closing law of the GVs during the load rejection process: (a) variation of servomotor stroke with time and (b) relationship between the GV opening and servomotor stroke

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Fig. 8

Comparison of the rotational speed between simulations and experiments

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Fig. 9

Variation of various dimensionless power quantities in the pump-turbine with time during the load rejection process

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Fig. 10

Variation of absolute loss (EPRt) in the whole pump-turbine and the relative loss ratio (EPR/EPRt) in various components of the pump-turbine with the time during the load rejection transient: (a) EPRt in the whole pump-turbine, (b) EPR/EPRt in SV, GV and SC region, and (c) EPR/EPRt in DT, CR, and RN region

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Fig. 11

Specific distribution of normalized S˙‴D along the different relative spanwise heights in guide/SVs and the RN at various typical instants: (a) t = 0.03 s, (b) t = 0.03 s, (c) t = 0.03 s, (d) t = 4.8 s, (e) t = 4.8 s, (f) t = 4.8 s, (g) t = 6.72 s, (h) t = 6.72 s, (i) t = 6.72 s, (j) t = 18.53 s, (k) t = 18.53 s, and (l) t = 18.53 s

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Fig. 12

Specific distribution of normalized S˙D‴ in the draft tube region at various typical instants: (a) t = 0.03 s, (b) t = 4.8 s, (c) t = 6.72 s, and (d) t = 18.53 s

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Fig. 13

Distribution contour of normalized vorticity along the different spanwise relative heights in guide/SVs and the RN at various typical instants: (a) t = 0.03 s, (b) t = 0.03 s, (c) t = 0.03 s, (d) t = 4.8 s, (e) t = 4.8 s, (f) t = 4.8 s, (g) t = 6.72 s, (h) t = 6.72 s, (i) t = 6.72 s, (j) t = 18.53 s, (k) t = 18.53 s, and (l) t = 18.53 s

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Fig. 14

Distribution contour of normalized vorticity in the draft tube region at various typical instants: (a) t = 0.03 s, (b) t = 4.8 s, (c) t = 6.72 s, and (d) t = 18.53 s

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