For atmospheric dispersion studies, in the case of a liquefied gas pipe rupture, the source term at the level of the breach is generally based on the assumption of a leak in the liquid phase, totally neglecting upstream vaporization in the pipe.
This assumption is highly penalizing in terms of leakage mass flow rate, does not reflect reality and thus leads to an overestimation of the quantity of material released.
The aim of this study is to develop and validate a numerical model to determine the flow and vaporization of the fluid in the pipe, in order to obtain, in fine, the leak rate and the vacuum rate at the leak.
To this end, we developed and validated a phase-change model of the adiabatic expansion of liquefied gas.
This model has enabled us to highlight a number of results, such as the marked influence of geometric singularities in the pipe (valve, elbow) in the event of total rupture: the pressure drop zones they generate concentrate most of the vaporization of the liquid phase, drastically increasing the void ratio.
The new models developed by OptiFluides take into account the vaporization of liquefied gas to provide you with even more accurate results.
