An inlet device capable of suppressing a saddle-shaped curve of pumping head of an axial flow pump

Abstract

The invention belongs to the technical field of hydraulic machinery and equipment and discloses an inlet device capable of suppressing a saddle-shaped curve of pumping head of an axial flow pump. The inlet device mainly comprises an inlet pipe at the front end of the axial flow pump, an impeller, a lower runner chamber and an upper runner chamber, wherein the impeller is fastened on a shaft through a key and an impeller nut, and the inlet device is characterized in that the inlet pipe is connected with the lower runner chamber, and a radial clearance exists between the inlet pipe and the lower runner chamber. The inner wall of the inlet pipe is shaped like a trumpet, ribbed plates are uniformly distributed on the outer wall of the inlet pipe, and flanges are arranged at the top parts of the ribbed plates. The outer diameter at the shrinkage tail end of the inlet pipe is less than the maximum outer diameter on the edges of blade inlets of the impeller; and the diameter at the shrinkage initial end of the inlet pipe is more than the outer diameter of the flanges and the maximum outer diameter of the ribbed plates. The inlet device disclosed by the invention can limit the deterioration of the axial flow pump in a flow field in the vicinity of an inlet of the impeller under a low-flow rate area, suppress the saddle shape in a pumping head-flow rate curve of the axial flow pump, increase the stability in operation of the axial flow pump and enable the axial flow pump to operate at full flow rate, and is suitable for most of the axial flow pumps.

Description

technical field [0001] The invention belongs to the technical field of hydraulic machinery equipment, and relates to a novel inlet device for axial flow pumps, especially suitable for large-scale pumping stations where the incoming water level constantly changes. Background technique [0002] The head-flow curve of traditional axial flow pumps often has a "saddle" shape. When the incoming water level drops to a certain level, the axial flow pump runs near the "saddle" area. At this time, the axial flow pump vibrates violently, causing damage to the unit. At present, there is no effective measure to solve this problem. Contents of the invention [0003] The purpose of the present invention is to suppress or even eliminate the "saddle" shape in the head-flow curve of the axial flow pump and realize the full flow operation of the axial flow pump, and propose a water inlet device for the axial flow pump. [0004] The purpose of the present invention is achieved through the fo...

AI Technical Summary

Problems solved by technology

[0002] The head-flow curve of traditional axial flow pumps often has a "saddle" shape. When the incoming water level drops to a certain level, the axial flow pump runs near the "saddle" area. At this time, the axial flow pump vibrates violently, causing damage to the unit.

At present, there is no effective measure to solve this problem

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