Analysis and comparison of calculation methods for physical explosions of compressed gases

Due to the complexity of the involved physical phenomena and to the lack of an adequate amount of reliable experimental data, a number of different models and calculation procedures for estimating the overpressure following the physical explosion of a compressed gas are presently reported in the literature. However, in many cases, only generic information about the main hypotheses adopted is provided and no guidelines about their accuracy, or range of applicability, are usually available. In the present paper the physical explosion of a compressed gas, released after the catastrophic rupture of its containment system, is addressed. The analysis is carried out by means of two of the most commonly used calculation procedures, which have been applied to a number of study cases, characterized by different substances, volume, geometrical configuration, and operating conditions. The obtained results are presented and compared. The analysis shows that, in all cases, the two methods give rise to different results, independently of the involved chemical, vessel size, and operating conditions. The dependence of the results on the main input parameters is highlighted in order to give a preliminary guideline in the selection of the proper calculation method for each specific study case.