Method for optimally designing impellers of bidirectional axial flow pumps

Abstract

The invention discloses a method for optimally designing impellers of bidirectional axial flow pumps. The method is characterized by comprising steps of designing hydraulic power on planar hydraulic power graphs of impellers in a central symmetry manner; completely modifying working faces of wing sections of the impellers into straight lines, enabling inlets and outlets of the backs of the wing sections of the impellers to be in circular arc transition, properly thickening the middles of the wing sections of the impellers and modifying the wing sections of the impellers into symmetrical structures; designing the impellers according to a plurality of main parameters including wrap angles phi of blades, diameters d<h> of hubs, diameters D of the impellers, setting angles beta<L> of lines, chord lengths I and radiuses R<1> of the lines. The method has the advantages that the performance of the impellers of the bidirectional axial flow pumps can be improved by means of optimizing the wing section and the planar graphs of the impellers on the basis of the traditional streamline method for designing impellers of axial flow pumps, and accordingly the purpose of improving the efficiency and the cavitation erosion resistance of the impellers of the bidirectional axial flow pumps can be achieved; high efficiency, a wide efficient range and the good cavitation erosion resistance of the bidirectional axial flow pumps can be guaranteed by the aid of the method, and the method is applicable to bidirectional axial flow pumps with the specific speeds ranging from 600 to 2000.

Description

technical field [0001] The invention relates to an optimal design method for an axial-flow pump impeller, and is especially suitable for the optimal design of a bi-directional axial-flow pump impeller used for bi-directional water pumping in a pumping station. Background technique [0002] The bidirectional axial flow pump is a special axial flow pump that pumps media in both directions through forward and reverse rotation. It is mostly used in special occasions such as bidirectional pumping stations and trains and ferries. However, as far as the two-way axial flow pumps studied are concerned, they are all modified and designed based on ordinary axial flow pumps, and many of them still use the unidirectional airfoil of ordinary axial flow pumps. In this way, when it is reversed, the efficiency and cavitation performance of the impeller will be greatly reduced, and in severe cases, the blade will lose flow and cause severe vibration and noise. Contents of the invention [...

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Problems solved by technology

In this way, when it is reversed, the efficiency and cavitation performance of the impeller will be greatly reduced, and in severe cases, the blade will fall off and cause severe vibration and noise.

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