Centrifugal compressor having an asymmetric self-recirculating casing treatment

摘要

A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. An axial distance S_r from an upstream end face of the suction ring groove 1 to an impeller full blade leading edge 4 or a width b_r of the suction ring groove 1 is represented as A·sin(α+θ₀)+A₀ and is distributed in a sinusoidal shape in a circumferential direction, an initial phase angle θ₀ is in a range of 0°≤θ₀≤360°, and a circumferential angle α of the casing 10 has a definition range of θ₀≤α≤θ₀₊360°. In the expression, A denotes amplitude of distribution of the axial distance S_r or the width b_r, and A₀ denotes an average of the axial distance S_r or the width b_r.