Application of Electrical Analogies for Simultaneous Modeling and Simulation of Gas Transmission Pipelines and Station Turbo Compressors

Gas flow modeling and simulation are essential for identifying and managing gas transmission networks, particularly when pipelines and turbo compressors are involved. This paper presents a methodological approach for simultaneous modeling of the gas transmission pipelines and station turbo compressors using an electrical analogy. For this purpose, the electrical analogy is initially applied to form electric circuits representing gas flow in pipelines. In this study, three electrical structures are proposed for the pipeline modeling: one for the steady state and two for the transient state. The idea of two transient structures is proposed in this study to use two different electric circuits for various boundary conditions usually given for the main and demand branch lines. In addition, electric elements are incorporated to model the turbo compressor and determine its fuel consumption. Using the methodology proposed in this study, the pressure and temperature drop along the pipeline, the performance and fuel consumption of the turbo compressors, the system settling time during flow rate changes, the impact of the demand branch lines on the gas flow rate of the main pipeline, and the influence of the demand on the line pack of the branches can be evaluated. The proposed methodology is evaluated using experimental data from a real gas transmission line with industrial compressors. Finally, the Iran Gas Trunkline is used as a case study to simulate gas flow in both steady and transient states by introducing three scenarios. The results obtained from the simulation of the case study demonstrate that the proposed approach is effective for simultaneous observation of the turbo compressor performance and gas behavior at any point along the main and branch pipelines.