Experimental analysis of a pressurized vessel exposed to fires: An innovative representative scale apparatus

One of the most critical safety issues concerning the transportation and the distribution of hazardous materials, is the possible occurrence of accidental fires affecting transport vessels, leading to the heat up and consequent failure with catastrophic effects. Therefore, since the early seventies, numerous field studies and laboratory scale tests were carried out on pressurized tanks, in order to simulate fire impingement conditions with the aim of increasing the understanding of such scenarios and improving the safety in this field. However, the detailed assessment of the inner fluid behaviour during fire exposure in terms of velocity, temperature and boundary layer determination was never object of detail investigation. This is critical for the development and validation of advanced modelling tools such as computational fluid dynamic (CFD), which is aimed at predicting vessel pressurization rate, time to failure and to support detailed safety and external emergency studies. With the aim of providing experimental data suitable for supporting the advanced modelling of fired vessels heat up and consequent pressurization, an innovative fire test set-up was designed for the present research work. Initial tests were carried out using water as operative fluid. The fire conditions, heated area, test fluid and filling degree can be varied among tests in order to investigate the influence of these parameters on the thermal and velocity profile in the tank lading. In the present work, the experimental set up is described and some preliminary results obtained during commissioning tests are summarized. The capabilities of the present apparatus in providing advanced results to support the evaluation of the behaviour of fired pressurized tankers are discussed.