| dc.description.abstract | When a loss of primary containment of liquefied natural gas (LNG) occurs on the ground, a pool, that simultaneously spreads and vaporizes, is formed posing cryogenic, asphyxiating, and flammable hazards to its surrounding. Determining the pool size and vapor generation upon release play key roles in the accuracy of dispersion and consequence models. This work focuses on expanding the available data to be used for LNG source term model validation through the evaluation of an existing model.
A field-scale experimental setup was designed to study the pool temperature, pool spreading and heat flux under the concrete, after a release. In this work, liquid nitrogen (LNv2) was used as a safer analogue to LNG as it is a non-toxic non-flammable cryogen. The experiments were carried out inside a 6×5×1.2 m pit. A vaporizing pool spreading model based on Gas Accumulation over a Spreading Pool (GASP) was then implemented and used to predict the vaporization and pool spreading rates of the spill. Finally, the model predictions were compared to the experimental data.
The results of this work gave insight to the validity of two existing source term models, the coupling of a pool spreading model with Fourier’s one-dimensional conduction heat transfer model. While the first model assumes that heat flux is uniform across the pool, the second model takes into account higher heat transfer due to exposure time difference between the outer rings of the pool to the center of the pool during pool spreading. Both models assume that the pool boils until it completely vaporizes. Experimental results indicate that the pool does boil until it completely vaporizes, and that the temperature at the center of the substrate was cooler than its outer parts. It was found that the model which accounts for higher heat transfer in the pool outer rings tends to underestimate pool size. Both models, however, overestimate the pool size at the early stages of the spill. As both models incorporate a solution of Fourier’s one-dimensional conduction equation, a comparison was also done between the predicted and experimental temperature. | en |
