Small-sized mixed-flow pump turbine for low water head pumped storage power station

Abstract

The invention relates to a small-sized mixed-flow pump turbine for a low water head pumped storage power station. The small-sized mixed-flow pump turbine for the low water head pumped storage power station is characterized in that the wrap angle of runner blades is 105-124 degrees, the included angle between the water inlet edge of each runner blade and the water outlet edge of the runner blade is 54-86 degrees, each runner blade is a three-dimensional distorted curved face, the thicknesses are equal in the perpendicular spine direction, the profile of each runner blade is crescent, the ratio value of the thickness of each runner blade to the height B1, existing under the working conditions of the turbine, of an inlet of each runner blade is 0.06-0.11, the height B1, existing under the working conditions of the turbine, of an inlet of each runner blade is equal to the height B2 of each guide vane, a wing of each guide vane is of a symmetrical whale shape, the upper canopy of each guide vane is provided with three pressure-relief vents which are evenly distributed, the axial section of a volute is round, a draft tube is of an elbow shape, and the axial section of the horizontal and straight section of the draft tube is round. By the adoption of the small-sized mixed-flow pump turbine for the low water head pumped storage power station, the water pump pumping working condition and the turbine electricity generation working condition which are opposite in directions of water flow pumped for two times, and the water turbine can efficiently operate under the two operation working conditions.

Description

technical field [0001] The invention belongs to the technical field of hydraulic machinery, in particular to a small mixed-flow pump-turbine used in a low-head pumped storage power station. Background technique [0002] With the rapid expansion and development of the power system, the functions of pumped storage power plants in the power system, such as peak regulation, frequency regulation, phase regulation and emergency backup, are becoming more and more significant. The pumped storage unit is the main unit of the pumped storage power station. The current pumped storage unit is mainly a reversible pump-turbine that can operate in both directions, and it has the functions of both a water turbine and a water pump. At present, there have been relatively in-depth researches on medium-high head and large-capacity pump turbines at home and abroad, and many experiences in design, optimization, and operation have been accumulated, and good results have been achieved. At the same ...

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Problems solved by technology

[0003] Chinese patent application 200810010743.1 discloses a "pump turbine", which provides a micro-pump turbine with simple structure, low cost, small flow rate, and small volume. The runner needs to be replaced when the working conditions are interchanged, which brings great restrictions to continuous production and operation; second, the manufacturing process of the airfoil blade is extremely complicated, and the dimensional accuracy is difficult to guarantee, which directly affects the operating efficiency

However, there are still the following obvious deficiencies: first, the shaft-extension tubular-flow pump-turbine adopts a straight-bent draft tube, and the tail water energy recovery efficiency is low, resulting in a decrease in the efficiency of the entire unit; Difficulty and environmental noise, and inconvenient operation and maintenance, so it can only be applied to small units; third, the processing of runner blades and guide vanes is difficult, the structure is complicated and the cost is high

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