AN ADVANCED OPTIMIZATION PROCEDURE FOR THE THERMODYNAMIC SELECTION OF CENTRIFUGAL COMPRESSORS STAGES

摘要

The present paper deals with the application of optimization algorithms to the selection of centrifugal stages for industrial compressors. The optimization procedure has been developed allowing an automatic stage selection to meet a mathematically stated target including the most relevant performance parameters and machine operating and size constraints.The thermodynamic selection is assessed by means of an internal-use CCS (Centrifugal Compressors Selector) that computes compressor flange-to-flange performance with a given sequence of stages.The CCS has been coupled to an internally used optimization code ("PEZ", Perl Version of Easy Optimizer) using the CCS as the performance evaluator. The user indicates which flange variables must be matched as well as the stages parameters that the optimizer is allowed to alter, with their respective ranges of acceptable variation. The optimization objective reflects the job specifications and can be stated as a combination of several performance parameters. Constraints are enforced through appropriate penalty terms added to the objective function.The performance optimization process includes an automatic rotordynamic analysis that checks the rotor mechanical acceptability.The optimization of two different in-line barrel compressors, originally configured manually, brought a remarkable 2% flange-to-flange performance increase and a 5% gain in operating range respectively. Each case required about 10 hours windows desktop workstation.