Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed
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...
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| Format: | Article |
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MDPI AG
2023-02-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/4/2071 |
| _version_ | 1811153813702180864 |
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| author | Jianxin Hu Wenfeng Su Ke Li Kexin Wu Ling Xue Guolei He |
| author_facet | Jianxin Hu Wenfeng Su Ke Li Kexin Wu Ling Xue Guolei He |
| author_sort | Jianxin Hu |
| collection | DOAJ |
| description | 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<sup>3</sup>/h, and it reached a peak at around 80 m<sup>3</sup>/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. |
| first_indexed | 2024-03-11T08:52:02Z |
| format | Article |
| id | doaj.art-9c5a0faa1c0a475593cd650ef22f0c95 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T08:52:02Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-9c5a0faa1c0a475593cd650ef22f0c952023-11-16T20:21:43ZengMDPI AGEnergies1996-10732023-02-01164207110.3390/en16042071Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating SpeedJianxin Hu0Wenfeng Su1Ke Li2Kexin Wu3Ling Xue4Guolei He5National-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaNational-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaNational-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaNational-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaNational-Provincial Joint Engineering Laboratory for Fluid Transmission System Technology, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaInstitute of Exploration Techniques, Chinese Academy of Geological Sciences, Langfang 065000, ChinaThe 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<sup>3</sup>/h, and it reached a peak at around 80 m<sup>3</sup>/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.https://www.mdpi.com/1996-1073/16/4/2071pump–turbinesvariable rotating speedstransient flow conditionsefficiencystability characteristics |
| spellingShingle | Jianxin Hu Wenfeng Su Ke Li Kexin Wu Ling Xue Guolei He Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed Energies pump–turbines variable rotating speeds transient flow conditions efficiency stability characteristics |
| title | Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed |
| title_full | Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed |
| title_fullStr | Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed |
| title_full_unstemmed | Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed |
| title_short | Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed |
| title_sort | transient hydrodynamic behavior of a pump as turbine with varying rotating speed |
| topic | pump–turbines variable rotating speeds transient flow conditions efficiency stability characteristics |
| url | https://www.mdpi.com/1996-1073/16/4/2071 |
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