Capacity control and performance optimization of variable geometry variable-speed centrifugal compressors

摘要

Variable speed operation offers the potential of increased centrifugal compressor efficiency at off-design conditions compared to variable geometry compressor control. However, this advantage of variable speed cooperation is offset by early (=low head) compressor surge. A combination of variable-speed and variable-geometry control is required to take advantage of the variable speed efficiency improvement without sacrificing low flow head capability. The paper describes the aerodynamic reasons for the necessity of a multi-input, multi-output compressor control if part-load performance is to be improved through the use of variable speed operation.