Reflux device for centrifugal compressor and centrifugal compressor having same

Abstract

The invention provides a backflow device for a centrifugal compressor and a centrifugal compressor with the same. The backflow device comprises a wall surface component, a blade connector, first-row blades and second-row blades. The wall surface component comprises gas supply openings. The blade connector is fixed to the wall surface component. The first-row blades include a plurality of first blades and are arranged on the blade connector. The second-row blades include second blades and are arranged on the blade connector. In the radial direction of the blade connector, the second-row blades are located on the inner sides of the first-row blades and each first blade is spaced from the second blade. The backflow device has the advantages that the gas separation phenomenon is reduced, the blade de-swirling effect is improved, the flow loss is reduced and the efficiency is increased; the wrap angles of the first-row blades and the second-row blades re reduced, so that the casting difficulty is reduced.

Description

technical field [0001] The invention relates to the field of compressors, in particular to a reflux device for a centrifugal compressor and a centrifugal compressor with the same. Background technique [0002] The return channel element is also called the reflux device. In the multi-stage centrifugal refrigeration compressor, its function is to guide the swirling gas with strong tangential velocity flowing out of the previous stage diffuser to the impeller inlet of the next stage. In order to obtain the best For optimal design performance, the impeller inlet airflow must enter the impeller in a direction with a tangential velocity of zero or close to zero (only retaining the axial velocity). The reflux device in the existing multi-stage centrifugal refrigeration compressor generally adopts the structure of single-row cascade derotation blades and part of the gas supply area, but there are the following problems: 1. The gas is easy to separate at the trailing edge of the blad...

AI Technical Summary

Problems solved by technology

The reflux device in the existing multi-stage centrifugal refrigeration compressor generally adopts the structure of single-row cascade derotation blades and part of the gas supply area, but there are the following problems: 1. The gas is easy to separate at the trailing edge of the blades, which reduces the derotation effect of the blades, and the flow The loss is large, and the efficiency of the reflux device is low; 2. Part of the gas supply area will cause uneven flow field at the rear, increasing flow loss and outlet mixing loss; 3. Single-leaf cascade derotation blade has a large wrap angle, which is not easy to cast and processing

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