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Numerical analysis on influence of vertical column on flow pattern in forebay and intake of large pumping station |
LI Yanyan, GUO Pengcheng*, SUN Longgang, ZHANG Huan |
State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi′an University of Technology, Xi′an, Shaanxi 710048, China |
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Abstract In order to study the influence of flow pattern in forebay on the efficiency and hydraulic stability of pumping unit. This paper takes a large pumping station as the research object, and the forebay was rectified based on three different additional column schemes. The research results show that adding a column has a better effect on improving the flow pattern of the forebay, and reduces the vortex intensity at the inlet of the suction horn pipe and the water pump, which is beneficial to improve the hydraulic stability of the unit. Under the condition that the flow loss was almost unchanged, the uniformity of the flow velocity of equal spacing single row plan, equal spacing double row plan and non-equal spa-cing double row scheme are increased by 3.13%,3.91% and 4.95%, respectively, and the average drift angle was reduced by 1.45%, 2.11% and 2.66%, respectively. Furthermore, the result show that the intensity of impeller inlet pressure pulsation was calculated by the non-equal spaced double-row scheme is significantly lower than that of the equidistant single-row scheme, and the peak value of the pulsation coefficient was reduced from 0.016 to 0.006. The comparison results show that the non-equal spaced double row scheme has a greater advantage in the front pool rectification. Therefore, the velocity distribution in forebay can be more uniform by adding non equidistant double row columns. The research results of the study can be used as a reference for similar hydraulic optimization measures in forebay settings.
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Received: 15 November 2020
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