A Thermodynamic Approach to the Enhancement of Reliability and the Optimization of Energy Efficiency of Centrifugal Compressors

The Aerothermodynamic performance of centrifugal compressors is substantially influenced by the variation in suction parameters and distortion in the internal clearances or the gas flow profile. Furthermore, deposits buildup can also affect the rotordynamic response of the system which can result in excessive vibration amplitudes due to the change in the synchronous dynamic forces acting on the rotor-bearing system. Therefore, thermodynamic performance analysis is an effective diagnostic tool for optimizing energy consumption and the reliability of the compressor through early prediction of machine failure and efficiency deterioration. This work introduces an approach to modeling and monitoring of the thermodynamic performance of centrifugal compressors. The approach relies on GERG-2008 equation of state for calculating gas properties at suction and discharge states. Additionally, Huntington 4-point method is used for evaluating the polytropic efficiency and polytropic head. A computer algorithm has been developed to Calculate the thermal and caloric properties of the gas at the compressor suction and discharge using GERG-2008 equation of state. In addition, it evaluates the polytropic head and efficiency using Huntington 4-Point Method. The program was also designed to Generate corrected performance maps based on the existing suction conditions and the manufacturer as-tested maps. The code can be run on historical data and produce trend plots for polytropic efficiency with temperature, pressure, flow rate, and speed. The calculated gas properties and polytropic efficiency were validated against literature results. Moreover, the developed algorithm was tested on several machines to assess their efficiency and energy consumption over different periods of time. The generated trends can be utilized to diagnose the root cause of efficiency degradation. Overall, the developed approach provides accurate and instantaneous results that can assist the compressor end-users in making critical decisions regarding the optimum time to halt operation of the highly demanding machines for carrying out major maintenance activities.