Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed

Jianxin Hu, Wenfeng Su, Ke Li, Kexin Wu, Ling Xue and Guolei He ()
Additional contact information
Jianxin Hu: National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, China
Wenfeng Su: National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, China
Ke Li: National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, China
Kexin Wu: National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, China
Ling Xue: National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, China
Guolei He: Institute of Exploration Techniques, Chinese Academy of Geological Sciences, Langfang 065000, China

Energies, 2023, vol. 16, issue 4, 1-17

Abstract: The working condition of a centrifugal pump as a turbine (PAT) is often unsteady. The rotating speed of a PAT constantly varies as the flow and load change, resulting in transient hydrodynamic behaviors between different working conditions. During the transition, the PAT undergoes a severe change in performance and complicated internal flow structures. In previous work, the fixed rotating speed of a PAT was mostly considered using computational fluid dynamics. To investigate the transient behavior of a PAT, relevant simulation tools are developed to depict transient flow conditions, and the corresponding transient speed of the impeller is calculated. Both large and small fluctuation transitions are simulated for the practical application of the PAT. The simulated results are first verified by experiments. The results show that the rotating speed significantly affects the performance and stability of the PAT. The rapid increment in flow rate and rotating speed lead to large energy dissipation in the internal flow field of the PAT. The range of high efficiency of the PAT expands and migrates to the high flow rate range. The efficiency in the transition condition started a cyclic growth after the flow reached 60 m 3 /h, and it reached a peak at around 80 m 3 /h, which was about 5% lower than the calculated value in a quasi-steady state. In the range of high rotating speeds, the rotating speed of the impeller and the operational stability are sensitive to flow fluctuation. The internal flow fields during transition conditions are analyzed as well. The obtained results can be utilized as a reference for studying the hydrodynamic characteristics and stability of fluid machinery in the transition under transient flow conditions.

Keywords: pump–turbines; variable rotating speeds; transient flow conditions; efficiency; stability characteristics (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://www.mdpi.com/1996-1073/16/4/2071/pdf (application/pdf)
https://www.mdpi.com/1996-1073/16/4/2071/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:16:y:2023:i:4:p:2071-:d:1074705

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().