Tutorial - Transient Flow In Gas Pipelines

This paper is a tutorial in unsteady-state natural gas flow. By way of two examples, the paper introduces the reader to the concepts of line pack management, accoustic wave travel, pipe line packing and d raftingoperations, as well as the practical implications of transients in system design and operation. quantity and quality is also presented. transient analysis. in the natural gas transmission environment is presented a long a brief discussion of "on-line" computer model. It is often valuable, when considering complex engineering techniques and procedures, to return to the basic principlas and assumptions which apply. so doing we can gain a perspective which is often lost after prolonged exposure to more complex and involved concepts. fundamentals is also valuable for those whose experience or education may not be specificallyoriented in these fields. intended as a "primer" on unsteady gas flow in natural gas pipelines. Literature is replete with papers covering the mathematics, physics and engineering aspects of gas flow from a much more rigorous perspective. contrast, this s paper's contribution is intended to enlighten the reader from a more intuitive and introductory perspective. In Such a review of the For these reasons, this paper is The In Steady-State Flow When gas is flowing through a be steady. Under this condit everywhere along the pipe and pipe a t a un on mass flow is equal to form flowrate the flow is said to into the pipe is equal to mass flow he mass flow leaving the pipe. Since the flow rate " in " equals the flow rate "out" there is no change with time in the volume of gas stored in the pipe. gas, at standard conditions, existing under pressure within a given volume of pipe, is called linepack. This inventory, the amount of In order to maintain gas flow in a pipeline, energy must be expended to overcome forces such as friction against the pipe wall and internal fluid shear, among others. gradient.