DEVELOPMENT OF UNSTEADY-STATE EQUATIONS FOR THE FLOW OF GAS THROUGH PIPELINES

摘要

Unsteady-state flow of natural gas in pipeline occurs more frequently in the design and operational analysis of natural gas systems. Most of the existing gas pipelines design procedures are based on steady-state flow equations. Hence there is the need to develop equations capable of calculating the unsteady-state gas volumetric flow rate in horizontal and inclined pipes. This paper presents unsteady-state equations for flow of natural gas through pipelines without neglecting any term in the momentum equation. The analytical solutions of the resulting differential equations are obtained. The equations give functional relationship between flow rate, inlet pressure and outlet pressure at any given time. The new unsteady-state equation yields results close to steady-state analysis but is able to account for the initial transience in gas flow rate. The equations considerably enhance gas pipeline design in terms of both ease of usage and accuracy. A simple computer program in FORTRAN is developed to handle these calculations.