Abstract

By manipulating the energy balance equation, gas flow equations describing flow in pipes can be expressed explicitly as functions of both pressure and temperature. The formulated equations in which pressure and temperature are considered as primary variables, form a system of equations which are nonlinear. An iteration procedure is required to solve such equations. The Newton-Raphson iteration method has been implemented to solve for pressure and temperature simultaneously. Using this model, pressure and temperature profiles for gas flow along a pipeline system can be predicted.

In this model, the formulated gas flow equations were derived by assuming that kinetic energy is negligible and the gas flow is in steady state. A phase behavior model and correlations are coupled to determine the gas fluid properties of the system.

The gas flow model was validated by comparing its predicted results to those predicted by other gas flow models e.g., the Weymouth and Panhandle models. Using this model, a parametric study was also conducted to ascertain the effects of elevation changes, temperature variaztion, pipe geometry, pipe orientation and different gas flow rates on the pressure and temperature profiles. The results demonstrate that the model can effectively model gas flow in pipelines.