Design and evaluation of rotor clearances for oil-injected screw compressors

Abstract

Designing twin-screw compressors to safely operate at higher than normal temperatures poses a challenge as the compressor must accommodate larger peak thermal distortions while maintaining efficiency at nominal operating conditions. This paper will present a case study of an oil-injected compressor tested at elevated discharge temperatures with original and revised clearances. A procedure is presented to use boundary conditions derived from a chamber model to approximate component temperature distributions that are then used to predict possible thermal distortions and the resulting effect on clearance gaps. The original and revised clearance designs are evaluated and performance penalties incurred due to the modifications are discussed.

Keywords

Twin-screw compressor boundary map rotor temperature thermal distortion clearances

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