Re-wheel and acoustic commissioning of an offshore centrifugal compressor

摘要

On the L9-FF-1 offshore platform, operated by NAM (Nederlandse Aardolie Maatschappij, a 50:50 venture of Shell and ExxonMobil), a centrifugal compressor installation has in the past led to high noise and vibration levels and impeller failures. After modification of the compressor impellers, no further failure occurred. However, significant high-frequency noise radiation remained, posing a major occupational noise exposure issue. The need for reduction of the noise radiation, combined with maintaining the capacity level led to the decision to re-wheel the existing installation. In close collaboration with NAM and TNO, Siemens applied various design changes to minimize noise emission. A maximum allowable noise level was a key requirement in the contract between NAM and the compressor manufacturer. To accurately evaluate the noise levels due to the new compressor design, a robust in-situ commissioning procedure was developed by TNO. After installation of the new bundle, noise levels were significantly reduced by 10-12 Db(A). The noise commissioning procedure was successfully applied to close out the contract between NAM and Siemens. This paper describes the noise issues related to the compressor re-wheel; it does not cover the root cause investigation of the impeller failure.