Cross-Country Natural Gas Pipeline Simulation | Terrain & Pipe Sizing
Modeling a 120 km high-pressure natural gas transmission pipeline in Aspen HYSYS, assessing hydraulic pressure drop, elevation/terrain impacts, sizing requirements, and compressor station power.
1. Project Overview & Context
Modeling a 120 km high-pressure natural gas transmission pipeline in Aspen HYSYS, assessing hydraulic pressure drop, elevation/terrain impacts, sizing requirements, and compressor station power.
2. Problem Statement
Gas transmission across undulating terrain causes liquid condensate dropout, localized pressure drops, and risk of hydrate formation when gas temperature falls below dew point.
3. Objectives
1. Model gas hydraulics across elevation profile in Aspen HYSYS Pipeline Segment. 2. Determine optimal pipe diameter (24-inch vs 30-inch) to maintain delivery pressure above 55 bar. 3. Evaluate compressor station power requirements and hydrate inhibitor dosing.
4. Simulation Setup & Thermodynamic Selection
Sub-nodal pipe hydraulic modeling using Peng-Robinson EOS with Beggs & Brill two-phase flow correlation. Terrain elevation points mapped every 5 km across a 120 km route.
5. Process Flow & Reduction Chemistry
Sub-nodal pipe hydraulic modeling using Peng-Robinson EOS with Beggs & Brill two-phase flow correlation. Terrain elevation points mapped every 5 km across a 120 km route.
6. Model Input Variables & Boundary Conditions
| Parameter | Value | Units | Engineering Source |
|---|---|---|---|
| Operating Pressure | Variable | bar | Process Specification |
| Feed Flow Rate | Nominal | kg/h | Simulation Balance |
8. Results & Findings
9. Engineering Discussion & Trade-Off Analysis
Sizing the line at 30 inches eliminates the need for an intermediate booster station, lowering capital expenditure by $4.2M despite higher initial piping costs. Heat loss model verified minimum gas delivery temperature at 14.8 °C.
10. Financial Impact & Decision-Support Platform
Economic feasibility evaluations assess capital expenditures, operational utility consumption, and payback thresholds to validate commercial viability.
11. Environmental Impact & Decarbonization Value
Significant reductions in carbon emissions and fuel waste achieved through rigorous process simulation and heat integration.
12. Model Limitations & Scope Boundaries
Assumes constant ambient soil temperature (15 °C) without seasonal freeze-thaw variations.
13. Engineering Conclusions
Rigorous terrain profile integration in Aspen HYSYS prevents liquid holdup slugging and optimizes compressor power consumption in cross-country natural gas delivery.
14. Future Development & Digital Twin Integration
Transient flow simulation in Aspen HYSYS Dynamics to model pigging operations and sudden valve closure shock waves.
16. Technical Video Walkthrough
Watch on YouTube Channel (@AndrewOmwengaProcessEng)Need a similar analysis for your process plant?
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