Air intake pipe structure for centrifugal fluid machine

Abstract

The purpose of the present invention is to provide an air intake pipe structure for a centrifugal fluid machine that, without using a mechanical means, is capable of reverse-rotating a fluid guided to an impeller and of improving the pressure ratio, during large flow volumes, and of forward-rotating said fluid during small flow volumes, thereby avoiding surging and maintaining a wide operation range. The air intake pipe structure (10) guides fluid (f) flowing in a substantially orthogonal direction relative to the axis of rotation (3) to the center of rotation (12a) of an impeller (12) housed in a housing (4), via an intake pipe (4a) for the housing (4) provided so as to protrude in the axis direction of a rotating shaft, in the centrifugal machine (1) having: the impeller (12) attached to the rotating shaft; and the housing (4) that houses the impeller (12). The air intake pipe (10) comprises an inflow section (14) extending in a substantially orthogonal direction to the axis of rotation (3), and a transition unit (16) connecting the inflow section (14) and the intake pipe (4a) for the housing (4); and is configured so as to have a virtual plane (20) configured such that the virtual plane is orthogonal to the axis of rotation (3) and passes through the flow path cross-section of the inflow section (14), and such that the point of intersection (22) with the axis of rotation (3) is positioned inside the transition unit (16).

Description

technical field [0001] The present invention relates to a suction pipe structure of a centrifugal compressor, a mixed flow compressor, a centrifugal blower, and a mixed flow blower (hereinafter, they are collectively referred to as a centrifugal fluid machine), which are one type of fluid machines. Background technique [0002] A centrifugal compressor that has an impeller rotating at a high speed and boosts the pressure of a fluid by centrifugal force is used in a turbocharger or a turbo refrigerator mounted on a vehicle or a ship. This centrifugal compressor requires a large operating range, but when the flow rate of the fluid leading to the centrifugal compressor decreases, the discharge pressure pulsates to generate surge that destabilizes the operating state, which becomes the operating limit. Therefore, in order to secure a large operating range in the centrifugal compressor, it is necessary to reduce the critical flow rate at which surge occurs. [0003] In order to ...

AI Technical Summary

Problems solved by technology

However, when the fluid directed to the impeller is swirled back, the surge line also shifts to the right side of the graph, so the operating range itself narrows

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