Improving the centrifugal compressor map through rigorous thermodynamic modeling: An analysis on a natural gas compression station pipeline

Abstract

This work proposes a way to describe the centrifugal compressor map for natural gas pipelines, aiming to apply it on a network online simulation. It updates the NASA shock loss theory by considering compressible flow inside the compressor governed by equations of state for real gases both to estimate the energy losses and to obtain the compressor map more accurately. Besides that, such a methodology can be used for any mixture of natural gas and compression systems. The simulations show that the proposed approach has a significant impact on the compressor map with a deviation of up 1.1 MPa, especially a displacement in the surge line, which delimits a larger unstable region than the conventionally unmodified approach. Moreover, the proposed corrections prove to be significantly crucial on the compression station of natural gas pipelines. The results allow evaluating the aptitude of the compressor for a natural gas pipeline and proving the reduction of operational costs obtained from the proposed approach. The simulations also show a mismatch of up 13.6% of energy consumption between the proposed description and the non-updated model, which implies that the proposed rigorous modeling proves to be quite adequate in the making-decision process.