PIPELINE LINE PACK CALCULATION
The natural gas line pack (inventory) in the high pressure pipeline of the National Natural Gas Transmission System (NNGTS) is calculated by the “PipelineStudio” software, created by the company Energy Solutions International (ESI) Ltd. and installed in the Gas Control & Dispatching Center, located in the premises of the Operation and Maintenance Center of the Southern Greece at Patima Magoulas near Athens. By using this software a hydraulic simulation model of the NNGTS network is created and contains all the network pipelines and their equipment in detail (i.e. diameter, length, wall thickness, positions, metering and/or regulating stations, line valve stations, scraper stations, etc.).
The high pressure network pipeline is divided into smaller pipes based on the data entered by the user of the software. Then the qualitative and quantitative elements of the natural gas are imported in the model (for example, pressure, temperature, gas analysis, etc.) so that the model converges to the operating parameters that the user needs. Finally, after solving a variety of equations, the software calculates the natural gas line pack in each divided part of the high pressure network pipeline.
The total line pack is the sum of the line packs of all the divided pipes.
