No abstract

No abstract

No abstract

No abstract

No abstract

As part of the Carbon Capture and Storage (CCS) process, pipeline transportation of dense phase CO2 is the safest and most economic option for delivering captured CO2 to a storage site .However, in the event of pipeline rupture an enormous mass of CO2 may be released very rapidly, presenting several risks to the pipeline and surrounding population including the significantly increased risk of brittle fracture in the pipe wall. The study of pressure variation and phase change in CO 2 during pipeline blowdown can contribute to the understanding of brittle fracture initiation and propagation, as well as downstream CO 2 diffusion behaviour. As part of the CO2QUEST project, a reusable, industrial scale pipeline experimental apparatus with a total length of 258 m and the inner diameter of 233 mm was fabricated to study CO 2 pipeline blowdown. A dual-disc blasting device was used to remotely control the opening of the pipeline, three different orifice diameters were used in experiments (15 mm, 50 mm and Full Bore Rupture). Different initial conditions in the inventory were achieved by heating the charged * Corresponding author.

a b s t r a c tThe development, testing and validation of a two-fluid transient flow model for simulating outflow following the failure of high pressure CO 2 pipelines is presented. Thermal and mechanical non-equilibrium effects during depressurisation are accounted for by utilising simple constitutive relations describing inter-phase mass, heat and momentum transfer in terms of relaxation to equilibrium. Pipe wall/fluid heat exchange on the other hand is modelled by coupling the fluid model with a finite difference transient heat conduction model. The two-fluid transient flow model's performance is tested by comparison of the predicted transient pressure and temperature profiles along the pipeline against those based on the simplified homogeneous equilibrium model (HEM) as well as real data captured during the full bore rupture of a 260 m long, 233 mm internal diameter pipeline containing CO 2 at 36 bara and 273 • C. The two-fluid model is found to produce a reasonably good degree of agreement with the experimental data throughout the depressurisation process. The HEM based flow model on the other hand performs well only near the rupture plane and during the early stages of the depressurisation process.

No abstract