• Title/Summary/Keyword: Fluid Machinery

Search Result 2,713, Processing Time 0.022 seconds

Study on Leading-phase Operation Capability of a 770 MW Jumbo Hydro-generator based on Stability Analysis and End-Region Heat Analysis

  • Fan, Zhen-nan;Zhou, Zhi-ting;Li, Jian-fu;Wen, Kun;Wang, Jun;Sun, Zhang;Wang, Tao;Yao, Bing
    • Journal of Electrical Engineering and Technology
    • /
    • v.13 no.3
    • /
    • pp.1317-1325
    • /
    • 2018

  • A generator-grid coupling calculation model is established to study the leading-phase operational capability of a 770 MW jumbo hydro-generator in a Chinese ultra-mega hydropower station. The static and dynamic stability of the generator are analyzed and calculated to obtain stability limits under leading-phase operating conditions. Three-dimensional (3D) time-varying nonlinear moving electromagnetic and temperature field models of the generator end-region are also established and used to determine the magnetic field, loss, and temperature of the end-region under the leading-phase operating condition. The simulation results agree with data measured from the actual 770 MW hydro-generator. This paper provides reliable reference data for the leading-phase operation of a jumbo hydro-generator, which will help to improve in the design and manufacture of future hydro-generators.

  • https://doi.org/10.5370/JEET.2018.13.3.1317 인용 PDF KSCI

Fluid-Structure Interaction Study on Diffuser Pump With a Two-Way Coupling Method

  • Xu, Huan;Liu, Houlin;Tan, Minggao;Cui, Jianbao
    • International Journal of Fluid Machinery and Systems
    • /
    • v.6 no.2
    • /
    • pp.87-93
    • /
    • 2013

  • In order to study the effect of the fluid-structure interaction (FSI) on the simulation results, the external characteristics and internal flow features of a diffuser pump were analyzed with a two-way flow solid coupling method. And the static and dynamic structure analysis of the blade was also caculated with the FEA method. The steady flow field is based on Reynolds Averaged N-S equations with standard $k-{\varepsilon}$ turbulent model, the unsteady flow field is based on the large eddy simulation, and the structure response is based on elastic transient structural dynamic equation. The results showed that the effect of FSI on the head prediction based on CFD really exists. At the same radius, the van mises stress on the nodes closed shroud and hub was larger than other nodes. A large deformation region existed near inlet side at the middle of blades. The strength of impeller satisfied the strength requirement with static stress analysis based on the fourth strength theory. The dynamic stress varied periodically with the impeller rotating. It was also found that the fundamental frequency of the dynamic stress is the rotating frequency and its harmonic frequency. The frequency of maximum stress amplitude at node 1626 was 7 times of the rotating frequency. The frequency of maximum stress amplitude at node 2328 was 14 times of the rotating frequency. No matter strength failure or fatigue failure, the root of blades near shroud is the key region to analyse.

  • https://doi.org/10.5293/IJFMS.2013.6.2.087 인용 PDF KSCI

Study of Cavitation Instabilities in Double-Suction Centrifugal Pump

  • Hatano, Shinya;Kang, Donghyuk;Kagawa, Shusaku;Nohmi, Motohiko;Yokota, Kazuhiko
    • International Journal of Fluid Machinery and Systems
    • /
    • v.7 no.3
    • /
    • pp.94-100
    • /
    • 2014

  • In double-suction centrifugal pumps, it was found that cavitation instabilities occur with vibration and a periodic chugging noise. The present study attempts to identify cavitation instabilities in the double-suction centrifugal pump by the experiment and Computational Fluid Dynamics (CFD). Cavitation instabilities in the tested pump were classified into three types of instabilities. The first one, in a range of cavitation number higher than breakdown cavitation number, is cavitation surge with a violent pressure oscillation. The second one, in a range of cavitation number higher than the cavitation number of cavitation surge, is considered to be rotating cavitation and causes the pressure oscillation due to the interaction of rotating cavitation with the impeller. Last one, in a range of cavitation number higher than the cavitation number of rotating cavitation, is considered to be a surge type instability.

  • https://doi.org/10.5293/IJFMS.2014.7.3.094 인용 PDF KSCI