A Method of Drilling 2 Holes in the Water Turbine Discharge Cone Based on Large Flow Deviated Working Conditions

Abstract

The invention provides a method for punching two holes in a runner cone of a hydraulic turbine based on a high-flow deviation condition. The method comprises the steps that pressure distribution on the runner cone and a draft tube is determined according to the large-flow deviation condition, so that a low-pressure region range and a vortex strip initial generation place are determined; the pressure distribution of the runner cone and the draft tube is symmetric, and a low-pressure region is located at an outlet of the runner cone; when the pressure is lower than local vaporization pressure, a cavity vortex strip, namely the vortex strip initial generation place will be generated; and punching measures are taken according to the vortex strip initial generation place, wherein the punching measures are that two holes are punched in the runner cone, and the runner cone with the two punched holes is configured in the way that the holes are punched oppositely along the axis center of the short-straight runner cone. Through the method, the problem of unsteady flow inside a hydraulic turbine set and particularly the problems of vortex strips and corresponding pressure pulsation in the draft tube in the prior art are solved.

Description

technical field [0001] The invention belongs to the technical field of water turbine stability, and in particular relates to a method for drilling two holes in a water turbine discharge cone based on a large flow and partial working condition. Background technique [0002] Today, as the importance of hydropower generation becomes increasingly prominent, the requirements for improving the operating efficiency of hydropower stations and the stability of hydraulic turbines have become particularly prominent. Among the factors affecting the stable operation of the turbine, the hydraulic factor is the most prominent, including the dynamic and static interference between the rotating part and the stationary part, the shedding of the blade surface, the cavitation blade path vortex, and the cavitation draft tube vortex belt, etc. During the operation of the turbine, most of these flow phenomena occur in off-the-shelf conditions that deviate from the design conditions, which will ind...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a method for drilling 2 holes in the discharge cone of the hydraulic turbine based on the large flow and partial working condition, so as to solve the unsteady flow problem inside the hydraulic turbine unit, especially the vortex zone in the draft tube And the corresponding pressure pulsation problem

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