(31b) Prediction of the Mass Flow of Heavy Gas Released from Standard Gas Bottles

In the presented study, the release process of heavy gases from standard gas bottles was investigated. A mathematical model has been developed to predict the mass flow for various release scenarios. This model takes into account the time-dependent temperature distribution of the bottle wall, a detailed description of the energy and mass balances as well as the possible occurrence of a two-phase flow. In order to validate the mathematical model a series of experimental investigations have been carried out. Comparisons between the experimental results and numerical predictions will be discussed. The model predictions and the experimental data show systematically good agreement. In particular, the occurrence and the duration of the two-phase flow could be accurately reproduced by the model. Special attention has been devoted to the maximum mass flow, because this mass flow has the largest impact on the subsequent gas dispersion. In addition to the experiments with the refrigerant R134a and CO2, theoretical calculations of the mass flow of chlorine were conducted. After having developed and validated such an accurate prediction tool for the time-dependent mass flow for any gas and any gas bottle geometry, it will become possible in a further step to analyze the near-field gas dispersion.