Accounting for Local Thermal Distortions in a Chamber Model for Twin Screw Compressors

Key

1300

Conference Year

2014

Authors

David Buckney, Howden Compressors Ltd., United KingdomFollow
Ahmed Kovacevic, City University London, Centre for Positive Displacement Compressor Technology, London, UKFollow
Nikola Stosic, City University London, Centre for Positive Displacement Compressor Technology, London, UKFollow

Keywords

twin-screw, compressor, modelling, thermal distortion

Abstract

A procedure is presented to estimate local clearance distortions in a twin screw compressor using boundary conditions derived from a chamber model. Time varying boundary conditions from the non-dimensional model are mapped onto rotor and casing surface arrays. The fluid boundary temperatures are time-averaged then used to estimate the local rotor and casing temperatures. Heat transfer assumptions that represent the extreme case for component temperature distributions are presented. The relative local change in clearances between rotors and casing are then investigated analytically. The effect of the revised clearances on the performance is quantified and compared against experimental results.