Analytical and computational indoor shelter models for infiltration of carbon dioxide into buildings: comparison with experimental data

This paper describes two indoor shelter models – an analytical model and a Computational Fluid Dynamics (CFD) model - that can be used to predict the level of infiltration of carbon dioxide (CO₂) into a building following a release from an onshore CO₂ pipeline. The motivation behind the development of these models was to demonstrate that the effects of shelter should be considered as part of a Quantitative Risk Assessment (QRA) for CO₂ pipeline infrastructure and to provide a methodology for considering the impact of a CO₂ release on building occupants.A key component in the consequence modelling of a release from a CO₂ pipeline is an infiltration model for CO₂ into buildings which can describe the impact on people inside buildings during a release event. This paper describes the development of an analytical shelter model and a CFD model which are capable of predicting the change in internal concentration, temperature and toxic load within a single roomed building that is totally engulfed by a transient cloud of gaseous CO₂. Application of the models is demonstrated by comparison with experimental measurements of CO₂ accumulation in a building placed in the path of a drifting cloud of CO₂. The analytical and CFD models are shown to make good predictions of the average change in internal concentration. Furthermore, it is demonstrated that the effects of shelter should be taken into account when conducting QRA assessments on CO₂ pipelines.