Aerodynamic and Rotordynamic Performance of a Multi-Stage Centrifugal Compressor With High Hub Impellers

Abstract Multi-stage centrifugal compressors with single shaft modular rotor designs are used extensively in the oil and gas industry. These compressors are designed to handle a wide range of speeds, flows and discharge pressures, in addition to handling a wide range of gas specific gravities. In this paper, low pressure test results are presented for a multi-stage centrifugal compressor with high hub impellers. Scaled results from a test rig are presented to validate the aerodynamic performance characteristics of a single stage of compression. The results of the scaled test rig are used to generate the performance characteristics of a family of impellers intended for use on the high-pressure compressor product line. A multi-stage compressor was built to validate the full-scale performance and the stage stack-up characteristics. Rotordynamic performance results of the free-free natural frequencies and unbalance response characteristics are presented for the full-scale compressor rotor. These results are used to validate the rotor-bearing models for the compressor rotor. Aerodynamic test results with discharge pressures up to 1,100 psia [76 bara] are presented. Test results obtained on nitrogen and carbon dioxide at multiple machine Mach numbers are also presented. The test results serve as a benchmark for the performance validation prior to intended usage at discharge pressures up to 4,900 psia [337 bara].