A Conical Water Inlet Device for Improving the Unstable Hydraulic Characteristics of Axial Flow Pumps

Abstract

The invention discloses a conical water inflow device for improving the instability hydraulic characteristic of an axial flow pump. The two ends of an outer sleeve serve as an inlet end and an outlet end respectively, an outlet flange is arranged on the outer wall of the outlet end, the outlet end of the outer sleeve is connected with the inlet end of an impeller chamber of the axial flow pump through the outlet flange, an inlet flange is arranged on the outer wall of the inlet end of the outer sleeve, and the inlet end of the outer sleeve can be connected with a water inflow pipeline through the inlet flange. An inner sleeve is arranged in the outer sleeve, a gap is formed between the inner sleeve and the outer sleeve, a rib plate is arranged in the gap, the inner sleeve and the outer sleeve are fixedly connected through the rib plate, and a vortex suppression plate is arranged on the inner wall of the inner sleeve. The inflow condition in front of an impeller under the small-flow working condition is fully improved, a hydraulic instable saddle region of the axial flow pump is completely eliminated, and the safe and stable operating working condition range of the axial flow pump is effectively widened. The conical water inflow device is simple in structure, easy to machine and manufacture and suitable for axial flow pumps of any types.

Description

technical field [0001] The invention belongs to the technical field of water pumps, and in particular relates to a conical water inlet device for improving the unstable hydraulic characteristics of an axial flow pump. Background technique [0002] Axial flow pumps have the characteristics of large flow and low head, and are widely used in fields such as cross-basin water transfer, agricultural irrigation, and municipal water supply and drainage. Under the design conditions, the axial flow pump has good water inlet conditions and stable internal flow. At this time, the hydraulic efficiency of the pump is high and the operation is stable. However, under non-design conditions, especially low flow conditions, the change of the inflow angle at the impeller inlet not only causes flow separation at the inlet edge on the back of the blade, but also increases the pressure difference between the upper and lower surfaces of the blade and enhances the tip clearance leakage flow. The fl...

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Problems solved by technology

[0003] The purpose of the present invention is to propose a conical water inlet device for improving the unstable hydraulic characteristics of the axial flow pump in view of the shortcomings of the existing conical water inlet device for improving the unstable hydraulic characteristics of the axial flow pump, without affecting the design flow and When the hydraulic performance of the pump is greatly affected under the condition of large flow rate, the water inlet condition before the inlet of the impeller of the axial flow pump under the condition of small flow rate can be fully improved, and the generation of unstable "saddle area" of the axial flow pump can be completely eliminated. Effectively broaden the stable operating range of axial flow pumps

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