A New Methodology for Verifying Pressurized Start-Up of Centrifugal Compressors Driven by Direct-On-Line Electric Motor by Leveraging String Test Results and Dynamic Simulation Analysis

Abstract

Fixed-Speed Electric Motors driving Centrifugal Compressors are designed considering the pressurized start-up as the most critical condition in terms of the torque requirement. Their capability is checked during the design phase by means of dynamic simulation, which may suffer from uncertainties, especially in the low speed range. When a Complete Unit Test is requested by purchaser, on top of the defined scope, it can be exploited to validate and refine the dynamic simulation so to predict more accurately the behavior of the compressor train at site conditions and confirm the capability of the driver to start-up the compressor from Settled-Out condition. The present paper describes a new methodology to leverage Direct-On-Line Centrifugal Compressor Complete Unit Test results to improve predictability of on-site pressurized start-up thanks to an enhanced dynamic simulation model. A case study is also presented showing how the methodology has been successfully applied to a re-injection compressor string.