A Parametric Study of Surge and Flow Instabilities in Gas Pipeline Compression Systems: The Effect of Pipe Parameters on Surge Margins

There is a need to understand the effect of coupling of the flow characteristics of a compressor with that of the pipeline and how this coupling effect the stability of the flow in a compression system. This study addresses such a need by carrying out a numerical simulation of the flow in the whole compression system including the compressor, the pipeline, and the other associated flow elements. A nonlinear, one-dimensional mathematical model is adopted for the present study. In this model, the gas flow inside the pipeline is assumed one-dimensional, viscous, and compressible. A parametric study is carried out using the proposed model, with air as the working fluid, to predict the surge margins for a subscale compression system and to study the effect of pipe length and diameter on these margins. Furthermore, the effect of these geometrical parameters on the amplitude and frequency of the flow oscillations are also established by numerical experimentation.