Analysis of Dynamic Behavior of Gas Pipelines as Result of Flow Rate Changes

In case of studying and modeling gas flow in the pipeline network, there are two types of flow: steady flow and transient flow. The natural gas pipeline network consists of pipelines, pressure compressor stations, pressure reduction stations, line break valves and storage fields. The pipeline is the key element in determining the overall network dynamic behavior. Dynamic behavior of a gas pipeline due to changes of gas flow rate for isothermal transient status has been modeled and investigated in this study. The modeling of isothermal transient flow is resulted in differential equations using mass conservation equations, momentum and an equation of state. By solving these equations according to time and place, the behavior of gas pipeline will be obtained. Three cases of the operating conditions for gas transmission pipelines in transient status have been studied. The modeling results of each case have been shown and interpreted in curves of flow rate and pressure variations along pipeline in different time spots.