Mixed vortex strip eliminating device for draft tube

Abstract

The invention relates to a mixed vortex strip eliminating device of a draft tube, which is arranged in a diffusion section of the draft tube and comprises a vortex generator and a vortex eliminating device, the vortex generator comprises at least three pairs of metal blades which are uniformly fixed on the inner circumferential wall of the diffusion section at intervals; the vortex eliminating device is located on the rear side of the vortex generator. The vortex eliminating device comprises an umbrella-shaped vortex eliminating mechanism and a fixing support. The umbrella-shaped vortex eliminating mechanism comprises a base and a vortex eliminating plate; the fixed bracket is vertically fixed on the inner circumferential wall of the diffusion section; the base is fixed on the fixed bracket; the base is located on the central axis of the diffusion section. The front ends of the at least three vortex eliminating plates are arranged on the periphery of the base; the tail end of the vortex eliminating plate faces the tail end of the diffusion section, and the tail end of the vortex eliminating plate is far away from the central axis of the diffusion section.

Description

technical field [0001] The invention relates to a device for mixing and eliminating vortex bands of a draft water pipe, belonging to the technical field of fluid machinery. Background technique [0002] The draft tube is an important energy recovery component in the turbine, and its performance directly determines the overall efficiency of the turbine unit. The working efficiency and stability of the draft tube mainly depend on the internal water flow characteristics. Under normal circumstances, the movement of the water flow inside the draft tube is very complex, with different pressure gradients in different directions, accompanied by the wake and the "horseshoe vortex" and "cutting vortex" in the flow channel. The flow has a strong vortex, which is very The complex three-dimensional motion of unsteady viscous fluid is inconvenient to be simulated and tested with advanced technical equipment. [0003] Therefore, in order to change the vortex of the water flow in the draf...

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Problems solved by technology

[0005] However, the vortex generator alone is not enough to deal with the vortex under complex working conditions.

For example, when the water flow in the draft tube is small, the flow state in the draft tube is poor and more vortices are generated, which will cause severe water pressure fluctuations, which will lead to low efficiency of the turbine unit; seriously, It may even affect the safe operation of hydropower units

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