Radial-axial flow turbine employing novel guide blade and runner blade profile

Abstract

The invention belongs to the technical field of fluid machinery and engineering equipment, and in particular relates to a radial-axial flow turbine, in particular to a radial-axial flow turbine employing a novel guide blade and runner blade profile. The turbine comprises a volute, a fixed guide blade, a movable guide blade, a runner and an exhaust water pipe; the shape of a nose baffle of the volute and the shape of the movable guide blade are designed, and a brand-new guide blade profile, so the flow is smoother, and the resistance loss in a flow channel is lower; the height difference between an upper crown and a lower ring surface, the length of a straight cone of the exhaust water pipe and a flow angle of outlet liquid of the turbine blade are newly designed; and a novel thickness change rule is adopted for the runner blade from an inlet to an outlet. The novel turbine improves the efficiency, reduces the vibration and pressure fluctuation, improves the mechanical strength of the runner, and reduces dynamic stress of the runner blade. Therefore, the probability for generating cracks on the runner blade is greatly reduced, and the operating stability of the turbine is improved.

Description

technical field [0001] The invention belongs to the technical field of fluid machinery and engineering equipment, and particularly relates to a Francis water turbine, in particular to a Francis water turbine adopting a new guide vane profile and runner blade thickness distribution rules. Background technique [0002] A number of Francis turbine units with a water head section of 80 meters have been built in China, with various forms of flow channels. [0003] The main feature of the flow channel is that the runner adopts X-shaped blades, that is, the inlet adopts a negative inclination angle, and the water outlet side is twisted, which is X-shaped when viewed from the runner inlet side. The blade form can better adapt to the water head and load with large fluctuations, and makes the pressure and velocity distribution in the blade passage more uniform. At present, the common defects of this type of water turbine unit are poor operation stability, large vibration and pressure...

AI Technical Summary

Problems solved by technology

At present, the common defects of this type of water turbine unit are poor operation stability, large vibration and pressure pulsation, and large dynamic stress on the runner blades, which can easily cause cracks in the runner blades.

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