Matching of Gas Turbines and Centrifugal Compressors: Oil and Gas Industry Practice

Abstract

Gas turbine driven centrifugal compressors are widely used in the oil and gas industry. In evaluating the optimum selection of gas turbine drivers for centrifugal compressors, one of the main objectives should be to verify proper integration and matching of the centrifugal compressor to its gas turbine driver. Gas turbines are of standard designs, while centrifugal compressors are specifically designed to meet customer requirements. The purchaser should clearly specify process requirements and define possible operating scenarios for the entire life of the gas turbine driven centrifugal compressor train. Process requirements defined by the purchaser, will be used by the compressor designer to shape the aero-thermodynamic behavior of the compressor and characterize compressor performance. When designing a centrifugal compressor to be driven by a specific gas turbine, other design requirements are automatically introduced to centrifugal compressor design. Off-design performance, optimum power turbine speeds at site conditions as well as optimum power margin required for a future-oriented design must all be considered. Design and off-design performance of the selected gas turbine at site conditions influences the final selection of a properly matched centrifugal compressor design. In order to evaluate different designs and select the most technically viable solution, the purchaser should have a clear understanding of the factors influencing a proper match for a centrifugal compressor and its gas turbine driver. This paper discusses criteria for evaluating the most efficient combination of a centrifugal compressor and its gas turbine driver as an integral package from a purchaser’s viewpoint. It also addresses API standard requirements on gas turbine driven centrifugal compressors.