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24 Pages·2012·0.84 MB·English

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n Dynamics in Natural Gas Lines
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A Pig Velocity Profiling
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Dr. Aidan O’Donoghue
[email protected]
www.pipeline-research.com
Presentation Content
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•Motion of single pigs in gas pipelines;
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Why model pig velocity?
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e •Desire to have pigs run in a controlled fashion;
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•Loss of inspection data;
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•Damage (pig, assets) and possible injury;
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•Analysis for investigations;
•Interpretation of
data logger output.
Basis of model
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Upstream Downstream
Velocity
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Two simultaneous PDEs: -
•Continuity - f(Pressure, Velocity);
•Momentum - f(Pressure, Velocity).
Solve for pressure and velocity against time and distance
Boundary conditions (BC) and initial conditions (IC)
Animation of Basic Equations
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Pressure at location in the line against time
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SimulinkTM Model for Pig Velocity
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Scope 6
Output
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Pig in 30 bars line with tight section of pipe
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Pig in 100 bars line with tight section of pipe
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Excess Pressure converted to Kinetic Energy
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Excess pressure is translated into high velocity
High acceleration due to low mass