Rotating wheel design method of ultrahigh water head section mixed flow water turbine with guide blades

Abstract

The invention discloses a rotating wheel design method of an ultrahigh water head section mixed flow water turbine with guide blades. The method comprises the following steps: (a) the guide blades androtating wheel blades are alternately arranged on a rotating wheel at intervals; and the guide blades are shorter than the rotating wheel blades; (b) included angles between water inlet edges of therotating wheel blades on two sides of the guide blades relative to the center of the rotating wheel are pitch angles theta 1; included angles between water inlet edges of the guide blades and water inlet edges of the rotating wheel blades on the sides of positive pressure surfaces of the guide blades relative to the center of the rotating wheel are pitch angles theta 2; the water head height is 455-790 m; the ratio of theta 2 to theta 1 is 0.42-0.60; and the ratio of theta 1 and theta 2 is reduced along with increment of the water head height; and (c) the ratio A / B of distances A to distancesB from water outlet edges of the guide blades to the rotating wheel blades on two sides is 1. The rotating wheel design method of the ultrahigh water head section mixed flow water turbine with the guide blades is suitable for ultrahigh water head sections, and improves the power generation efficiency of rotating wheels of hydraulic system prototypes.

Description

technical field [0001] The invention belongs to the field of water turbines, and in particular relates to a design method for a runner of a mixed-flow water turbine with guide blades and a super-high water head section. Background technique [0002] According to the different energy conversion types of the hydraulic turbine structure, the applicable water head range is also different. Different structural forms of hydraulic turbines will obviously affect the scale of civil engineering of the power station, the manufacturing cost of the unit and the reliability of operation. High water head above 250m, super high water head above 400m, 600m-700m has reached the theoretical limit of Francis turbine, and the development and design are very difficult. At present, the Francis hydropower station with the highest water head in China has a maximum water head of 551.7 meters and a turbine output of 82MW. The turbine energy index (power generation efficiency) of the high head unit is...

AI Technical Summary

Problems solved by technology

Due to the high technical difficulty of high water head mixers, there is a technical gap in the technology of ultra-high water head units above 600m in China, and there is no independent development and application of Francis hydroelectric generating units above 600m in China

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