 |
| Titel |
High pressurized CO2 release CFD calculations from onshore pipeline leakages |
| VerfasserIn |
Nicoleta Herzog, Paul Gorenz, Christoph Egbers |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250073283
|
|
|
|
|
|
| Zusammenfassung |
| Emissions from high pressurized pipelines can be determined on the basis of hydrodynamical
and thermophysical calculations of the escaped fluid. If a rupture occurs when CO2 is
onshore transported in liquid form there will be initially a large pressure drop in
the pipeline, the pressure will fall until the liquid becomes a mixture of saturated
vapor/liquid. In the vicinity of the rupture, liquid CO2 will escape and immediately
vaporize and expand, some of the liquid will desublimate into dry ice, which will
precipitate onto the ground [1, 2]. The period of time taken for a large amount of carbon
dioxide to be discharged would be short. Initially CO2 will escape by pushing the
overlying soil upwards at an explosion-like speed. After the pressure in the pipe
fell the flow profile of the escaping gas will almost be as described for gaseous
material transport. The expansion of carbon dioxide will occur at sonic speed and will
continue to do so until the pressure ratio between the CO2 and the ambient air is
lower than about 1.9 [3]. As a result of the expansion also the temperature of the
escaping gas will fall drastically and a cloud of cold gas will form which is then
dispersed and slowly mixed with ambient air. The rate of emptying the pipeline is
controlled by the pipe cross-section area and the speed of the escaping gas, or by the
pressure difference between the pipeline and the atmosphere. Therefore the mass
flow will be largest immediately after the accident with an exponential decay in
time.
In this study a two-phase model is applied to a high pressurized pipeline through which
liquid carbon dioxide flows. A leakage is considered to be at different positions along the
pipeline and the release pressure is calculated over several parameter ranges. It is also
intended to characterize from hydrodynamical point of view the dispersion of released CO2
in the ambient medium by means of CFD simulations which includes multiphase flow
treatment. For that a turbulent two-phase CFD model is used to analyze the influence of the
jet release pressure and leakage dimension on the harmful gaseous CO2 concentration
distances.
Mazzoldi A., Hill T., Colls J.J.: CO2 transportation for carbon capture and
storage: Sublimation of carbon dioxide from a dry ice bank, Int. J. Greenhouse
Gas Control, 2, 210-218 (2008)
M. Molag, C. Dam: Modelling of accidental releases from a high pressure CO2
pipelines, Energy Procedia, 4, 2301-2307, (2011)
Kruse H., Tekiela M.: Calculating the consequences of a CO2-pipeline rupture,
Energy Conversion and Management, 37(68), 1013-1018 (1996) |
|
|
|
|
|
|