Estimation of Flow Capacity in Pipelines Based on the Intrinsic Variation of the Volumetric Properties of the Natural Gas Mixture

In this paper, the Weymouth equation was applied so as to consider the pipeline characteristics, thermodynamic and physical gas properties. From literature, volumetric parameters like the specific gravity and compressibility are mostly assumed to be consta nts. Since they are related to flow, pressure and temperature values; neglecting their variation during pipeline transportation may lead to significant misleading results in the computation of pipeline resistance. Considering that providing global optimal solutions to instances of considerable size can become time - consuming , thus a mathematical optimization method was applied to find the solution that will satisfy these systems. Critical property correlations (Thomas, Standing and Sulton) and Compressibilit y correlations (Hall - Yarborough, Danchuk - Purvis - Robinson are used mathematically to generate results that will optimize the gas pipeline transportation without assuming specific gravity and compressibility factor of the gas constant. The model proposed in this study showed that specific gravity and compressibility have an effect on gas pipeline flow rate. It was observed that at very low and very high specific gravity, that the gas flow rate is reduced by more than 10% while the gas density increases. It ca n also be stated from the results that, compressibility is directly proportional to flow rate and inversely proportional to density.