A Model for Predicting Flowing Gas Temperature and Pressure Profiles in Buried Pipeline

Steady sate flow of natural gas in buried pipeline is predicted with both the heat transfer between the flowing gas and the surrounding and the Joule-Thompson effect. The steady-state flow continuity, momentum and energy equations constitute the governing equations. As a constant gas mass flux (or gas mass flow rate) distribution along the pipeline is obtained from the steady-state continuity equation, the mathematical model describing steady-state gas flow in pipeline may be reduced to a second-order ODE system of first-order initial-value problem with gas pressure and temperature as the dependent variables. The forth-order Runge-Kutta method is used to solve this ODE system. Comparison between the predicted results and the observed field data are very good.