Design method of an axial-flow low-lift front inducer

Abstract

The invention provides a design method of an axial-flow low-lift front inducer, and the inducer is suitable for centrifugal pump units with medium and low specific speeds widely used in fields such as petrochemical, smelting and power plants. It gives the main geometric parameters of the inducer, the diameter of the outer edge of the inducer D, and the diameter of the hub of the inducer D h , blade inlet edge inclination angle α, inducer outlet edge diameter D o , the inducer hub cone angle θ, the radius R of the airfoil working surface of the flow surface A p , the design formula of airfoil outlet placement angle β and airfoil chord length l. The low-lift front inducer designed by the invention can improve the flow field distribution at the inlet of the centrifugal pump, and can be applied to the occasion of medium containing solid particles, effectively improving the operation stability of the impeller of the centrifugal pump under low device NPSH sex and inhalation properties.

Description

technical field [0001] The patent of the present invention relates to a design method of an axial-flow low-lift front inducer, specifically, a design method of a front inducer suitable for improving the cavitation performance of a chemical centrifugal pump with a medium and low specific speed. Background technique [0002] The inducer is a blade-type rotating machine used to increase the NPSH of the impeller inlet device of the centrifugal pump. It was first used in the engine fuel delivery pump in the aerospace field and other occasions. It has low blade load, small number of blades and suction performance. Good features can increase the medium pressure at the impeller inlet and effectively improve the cavitation at the impeller inlet of the centrifugal pump. With the expansion of various industrial application fields, inducers are widely used in many medium and low specific speed centrifugal pump units in petrochemical, smelting and power plant fields. Conventional induce...

AI Technical Summary

Problems solved by technology

Conventional inducers mostly adopt a cylindrical helical axial surface structure, the blade distribution adopts a fixed pitch or variable pitch design, and the blade shape is mainly a flat structure. The size parameters of this inducer structure are easy to design, and the shape features are easy to manufacture and process. , but because the blade shape is too simple, the hydraulic efficiency and suction performance of the inducer itself are low, and there is a certain difference between the outlet flow field distribution and the design suction conditions of the centrifugal pump impeller, which has a certain impact on the suction performance of the impeller

In addition, because the flow channel of this type of inducer is long and the number of blades is large, it is easy to wear when conveying the medium containing solid particles, which easily causes the unstable operation of the centrifugal pump unit

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