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Investigation of the transient characteristics of the Francis turbine during runaway process

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  • Li, Yanyan
  • Sun, Longgang
  • Guo, Pengcheng

Abstract

Transient hydraulic phenomena, including flow separation, vortex structure and high amplitude pressure fluctuation, occur in the turbine during runaway process, significantly affecting the safe and stable operation. To clarify the unsteady flow characteristics in the runaway process, this paper focus on a low head model Francis turbine, examining the transient flow dynamics from rated speed to runaway speed. Numerical simulations show good agreement with experimental test results for the runaway speed and discharge. Results identify that two typical cavitation vortex structures within the runner: A cloud cavitation vortex near the hub on the pressure side and a columnar cavitation vortex on the suction side. Further analysis reveals that the pressure fluctuation induced by the former are low-frequency (0.08fn and harmonics), whereas those induced by the latter are high-frequency (1.16fn and harmonics). Entropy production analysis in homogeneous flow indicates that energy dissipation mainly occurs in the runner and draft tube during the runaway process. Turbulent entropy production within the turbine comprises a significant portion of the total entropy production. Additionally, areas around the recirculation zone exhibit considerable high entropy production, indicating that the energy of the fluid is dissipated by cavitation vortex structures generated in these areas. Additionally, the analysis indicates that the entropy production rate correlates with vapor generation, underscoring the cavitation vortex as the primary cause of energy dissipation. This investigation can provide valuable insights into the energy dissipation mechanisms during the runaway process.

Suggested Citation

  • Li, Yanyan & Sun, Longgang & Guo, Pengcheng, 2024. "Investigation of the transient characteristics of the Francis turbine during runaway process," Renewable Energy, Elsevier, vol. 237(PC).
    • Handle: RePEc:eee:renene:v:237:y:2024:i:pc:s0960148124019086
    DOI: 10.1016/j.renene.2024.121840
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    References listed on IDEAS

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    1. Lai, Xide & Chen, Xiaoming & Liang, Quanwei & Ye, Daoxing & Gou, Qiuqin & Wang, Rongtao & Yan, Yi, 2023. "Experimental and numerical investigation of vortex flows and pressure fluctuations in a high-head pump-turbine," Renewable Energy, Elsevier, vol. 211(C), pages 236-247.
    2. Kan, Kan & Xu, Zhe & Chen, Huixiang & Xu, Hui & Zheng, Yuan & Zhou, Daqing & Muhirwa, Alexis & Maxime, Binama, 2022. "Energy loss mechanisms of transition from pump mode to turbine mode of an axial-flow pump under bidirectional conditions," Energy, Elsevier, vol. 257(C).
    3. Sun, Longgang & Guo, Pengcheng & Luo, Xingqi, 2020. "Numerical investigation on inter-blade cavitation vortex in a Franics turbine," Renewable Energy, Elsevier, vol. 158(C), pages 64-74.
    4. Ji, Leilei & Li, Wei & Shi, Weidong & Chang, Hao & Yang, Zhenyu, 2020. "Energy characteristics of mixed-flow pump under different tip clearances based on entropy production analysis," Energy, Elsevier, vol. 199(C).
    5. Yu, An & Tang, Qinghong & Chen, Huixiang & Zhou, Daqing, 2021. "Investigations of the thermodynamic entropy evaluation in a hydraulic turbine under various operating conditions," Renewable Energy, Elsevier, vol. 180(C), pages 1026-1043.
    6. Rezghi, A. & Riasi, A., 2016. "Sensitivity analysis of transient flow of two parallel pump-turbines operating at runaway," Renewable Energy, Elsevier, vol. 86(C), pages 611-622.
    7. Sun, Longgang & Guo, Pengcheng & Yan, Jianguo, 2021. "Transient analysis of load rejection for a high-head Francis turbine based on structured overset mesh," Renewable Energy, Elsevier, vol. 171(C), pages 658-671.
    8. Chirag Trivedi & Michel J. Cervantes & B. K. Gandhi, 2016. "Investigation of a High Head Francis Turbine at Runaway Operating Conditions," Energies, MDPI, vol. 9(3), pages 1, March.
    9. Chen, Huixiang & Zhou, Daqing & Kan, Kan & Guo, Junxun & Zheng, Yuan & Binama, Maxime & Xu, Zhe & Feng, Jiangang, 2021. "Transient characteristics during the co-closing guide vanes and runner blades of a bulb turbine in load rejection process," Renewable Energy, Elsevier, vol. 165(P2), pages 28-41.
    10. Lu, Jie & Qian, Zhongdong & Lee, Young-Ho, 2021. "Numerical investigation of unsteady characteristics of a pump turbine under runaway condition," Renewable Energy, Elsevier, vol. 169(C), pages 905-924.
    11. Sotoudeh, Nahale & Maddahian, Reza & Cervantes, Michel J., 2020. "Investigation of Rotating Vortex Rope formation during load variation in a Francis turbine draft tube," Renewable Energy, Elsevier, vol. 151(C), pages 238-254.
    12. Feng, Jianjun & Ge, Zhenguo & Zhang, Yu & Zhu, Guojun & Wu, Guangkuan & Lu, Jinling & Luo, Xingqi, 2021. "Numerical investigation on characteristics of transient process in centrifugal pumps during power failure," Renewable Energy, Elsevier, vol. 170(C), pages 267-276.
    13. Goyal, Rahul & Gandhi, Bhupendra K., 2018. "Review of hydrodynamics instabilities in Francis turbine during off-design and transient operations," Renewable Energy, Elsevier, vol. 116(PA), pages 697-709.
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