Novel water turbine activity guide vane vertical surface gap optimizing method based on finite element analysis

Abstract

The invention discloses a novel water turbine activity guide vane vertical surface gap optimizing method based on finite element analysis. The tail shape of a water turbine activity guide vane is modified, the activity guide vane vertical surface gap can be reduced effectively, and the problem that large amount of water leaks when a unit is shut down is solved. According to the method, a contacting unit is utilized to simulate deformation conditions of water turbine activity guide vane hydrostatic shut-down conditions, and a gap, between the head and tail seal lines of a guide vane, calculating method can be derived according to geometry structure and arrangement position of the activity guide vane. Uneven shape modifying is performed on the tail sealed position of the activity guide vane according to acquired a vertical surface gap distributing curve so as to guarantee that the amount of shape modifying and that of the gap are canceled and allow the shape-modified guide vane vertical surface gap to be minimum. By the aid of the method, water leakage amount can be reduced effectively when the guide vane is closed, a large amount of water can be saved, and huge economical benefits are provided to a plant; and meanwhile, material cost increase since a manufacturer blindly pursuits guide vane deformation amount reduction is avoided.

Description

Technical field: [0001] The invention relates to a new method for optimizing the vertical clearance of movable guide vanes of water turbines based on finite element analysis. Background technique: [0002] When the hydro turbine is closed in still water, the deformation of the movable guide vane is relatively large, resulting in an increase in water leakage. Especially for axial flow turbines, due to the particularity of its structure, the height of the movable guide vanes is relatively high, and the amount of deformation also increases accordingly, resulting in more obvious problems of excessive water leakage. The usual measures are to increase the diameter of the guide vane pivot, widen the airfoil of the hollow movable guide vane, or even use a solid guide vane. However, the effect of reducing the amount of water leakage is not ideal, and the increase in the weight of the guide vanes will inevitably lead to an increase in material costs, which is extremely unfavorable to...

AI Technical Summary

Problems solved by technology

However, the effect of reducing water leakage is not very ideal, and the increase in the weight of the guide vane will inevitably lead to an increase in material costs, which is extremely unfavorable to guide vane manufacturers and power plants

The existing method for repairing the clearance of the façade of movable guide vanes is usually to remove 0-0.5mm thick material from bottom to top along the sealing line. Although the amount of water leakage can be reduced to a certain extent, the repair plan is blind and there is no Targeted, unable to meet the optimal design of guide vane facade clearance

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