Flow Evolution and Energy Loss Mechanism in Accidental Shutdown Process of a Large Submersible Mixed-Flow Pump System
عنوان مقاله: Flow Evolution and Energy Loss Mechanism in Accidental Shutdown Process of a Large Submersible Mixed-Flow Pump System
شناسه ملی مقاله: JR_JAFM-16-5_004
منتشر شده در در سال 1402
شناسه ملی مقاله: JR_JAFM-16-5_004
منتشر شده در در سال 1402
مشخصات نویسندگان مقاله:
B. Zhu - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
W. Han - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
Z. Tai - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
Y. Chen - Yangtze River Survey Planning and Design Research Co., LTD, Shanghai Branch, Shanghai ۲۰۰۴۳۹, China
خلاصه مقاله:
B. Zhu - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
W. Han - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
Z. Tai - School of Energy and Power Engineerning, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China
Y. Chen - Yangtze River Survey Planning and Design Research Co., LTD, Shanghai Branch, Shanghai ۲۰۰۴۳۹, China
To investigate the accidental shutdown process for a large vertical and submersible mixed-flow pump unit in a drainage pumping station, a three-dimensional numerical method for this transition process was proposed according to the angular momentum balance theorem and rigid body rotation technology. We obtained the transient performance curves of the unit and the internal flow characteristics of the full flow channel. In addition, we also analyzed the energy loss distribution of the through-flow components during this progress based on the entropy production theory. The results show that the whole runaway process needs to go through four stages: the pump mode, the pump braking mode, the turbine mode, and the stable runaway mode. The pressure amplitude changes greatly in impeller and guide vanes, and the main fluctuation frequency is the blade frequency. There are higher harmonic frequencies in the dynamic rotor-stator interface. As the rotating speed increases in turbine mode, the negative pressure area near the impeller blade’s trailing edge gradually increases. The entropy production method can be used to determine the location, intensity of energy loss during the transient process. If the rotating speed exceeds the allowed value in the runaway turbine mode, the interaction between blade tip vortex and hub vortex rope may cause loss of stability.
کلمات کلیدی: Vertical and submersible mixed-flow pump, Accidental shutdown, Transition process, Entropy production, Computational fluid dynamics
صفحه اختصاصی مقاله و دریافت فایل کامل: https://civilica.com/doc/1620327/