Shop Acceptance Testing Of Compressor Rotordynamic Stability And Theoretical Correlation

Lecturepg. 31-42This paper presents the rotordynamic stability testing of a nine-stage centrifugal compressor used for hydrogen recycle service. The machine tested was of a basic design and employed no damper bearings, damper seals, shunts or swirl brakes to generate very high logarithmic (log) decrements as in previous papers. The test was performed using an electromagnetic shaker as part of the shop order. Results include the forward and backward mode’s stability and frequencies. Two log decrement estimation techniques were employed: One based in the time domain that does not require measurement of the shaker force and the classic ones based in the frequency domain. Examination of the results benchmarks the original equipment manufacturer’s (OEM’s) stability analysis methods versus the measurements. It also provides benchmarking of purchaser’s acceptance criteria, which can be tailored to each specific OEM