(189f) Experimental Study of Accidental Industrial LPG Releases

The objective of the atmospheric dispersion research projects of INERIS are to develop models of flashing releases as encountered in realistic industrial environments. Equivalent source term models exist for flashing release in current long range dispersion models. Several factors can, however, invalidate simplified equivalent source models, especially in the very near field where obstacles can be found. To perform these objectives, INERIS took part in an European project called FLIE (Flashing Liquids in Industrial Environment). In this project, INERIS carried out large-scale experiments with propane and butane releases. The French ministry in charge of Environment also supported INERIS participation which dealt with the modelling of two-phase jets. This paper aims at presenting the large scale experiments and the main results. The experimental set-up is located in the INERIS test site. It allows performing propane and butane liquid releases at ambient temperature with a regulated pressure from the saturation pressure to 15 bar with an orifice (circular or rectangular shape) of an equivalent diameter from 10 mm to 25 mm. It is possible to realise free jets but also impinging jets by introducing obstacle at a maximum distance of 2 meters from the release point. To develop models requires experimental validation data. Up to now, little of experiments were carried out on a large scale with such a variety of measurements. The results revealed some new points related in particular to the rain-out which are rarely discussed in the literature and which can be useful to develop models of flashing releases. The most interesting point is relative to the granulometric distribution of the droplets forming the aerosol in the jet. Another important lesson learnt is that pools formed by LPG release jets do not contain liquid exclusively but also a mixture with ice. This has a great influence on the pool evaporation.