Verification of the Methodology for Determining Thermal Loads during Fireballs Formation

Abstract

An emergency scenario, in which a fireball is formed, is not uncommon. It happens as the result of rupture of the pressure vessel with the release of the superheated fuel. Hazard of the fireballs is significant thermal loads with a short lifetime. The existing methods of predicting the heat flow during the formation of the fireballs simplify the schematization of the process (assume the immobility of the ball), and, also, do not fully reflect the possible thermal loads. For this reason, the method for determining thermal loads was developed, considering the fireball movement. The purpose of this study is to verify the developed methodology for determining thermal loads accompanied by the fireballs based on a comparative analysis of the calculation results with the consequences of the explosion that occurred on 10.08.2020 in Volgograd. The objectives of the study: determination of the fireball kinematic parameters; based on the kinematic parameters, the calculation of the thermal loads occurred as the result of an accident; comparative analysis of the emergency consequences with the results of the thermal loads; comparative analysis of the results of the thermal load calculations with the results of heat flow calculations according to the existing regulatory documents. To check the operability of the fireball lifting model, the shooting frames of its formation were used. According to the shooting frames, the position of the fireball in space and its kinematic characteristics were tracked. Using kinematic parameters, the thermal loads were determined. To assess the adequacy of the thermal loads calculations, a comparative analysis of the calculation results of the developed methodology with the emergency consequence in Volgograd was used.