OLIVEIRA, T. C. L.; LINHARES DE OLIVEIRA, TALLES CAIO.; OLIVEIRA, TALLES CAIO LINHARES DE.; http://lattes.cnpq.br/0098804855877955; OLIVEIRA, Talles Caio Linhares de.
Resumen:
Industrially, flammable gases are stored and transported in the form of pressurized liquid.
The occurrence of leaks from pressurized flammable liquids in vessels or pipes may cause
a two-phase release containing a mixture of liquid droplets and vapour of flammable
substances, therefore the study of this type of release of fundamental importance for the
hazardous areas classification. The most important standard used for classification of
areas does not address cases where the release of liquefied gases is two-phase nature but
recommends the use of computational fluid dynamics (CFD) for these situations. In the
present work, a CFD model was defined to hazardous areas classification where possible
releases of liquefied gases can occur, for which the commercial software Ansys® CFX
16.1 was used. A detailed study of the release of the flammable two-phase jet was
conducted using propane and liquefied petroleum gas (LPG). The results showed that on
average for most simulated cases the extensions of the classified areas presented in the
standards are larger than those obtained by the model, resulting in oversizing of the
hazardous area for most of the cases analyzed. The influence of the wind was analyzed,
where it was verified that a gradual increase of the wind intensity in the same direction
of the release contributes to an increase in the extension and a reduction in the volume of
the explosive atmosphere. For low wind velocity and opposite direction to the leak, an
increase in the extent and volume of the explosive atmosphere was observed. The
simulations conducted in CFD with inert confirmed the effectiveness of the process of
inertization to reduce the hazardous area. Using the fluid dynamics model it was possible
to propose an equation to determine the extent of the explosive atmosphere, providing a
fast and accurate response, thus eliminating the high computational cost required by the
CFD. The numerical model results agree with available experimental results.