New measurement method for vaporization velocity for spreading cryogenic liquid

The study of liquid pool spreading plays an essential role in the quantitative risk assessment of accidentally released cryogenic liquids, such as LNG and liquefied hydrogen because the spreading of such liquids is the first step in the development of multi-staged accident sequences leading to a major disaster. There is a wide range of models used to describe the spreading of a cryogenic liquid pool. Some of these models require the vaporization velocity as an input parameter. However, other models can simultaneously predict the spreading and vaporization. The existing experimental method to estimate the vaporization velocity requires the knowledge of the spill rate, spreading data, and pool mass. In a practical release, however, it is not possible to obtain the pool mass data. In this work, the authors attempt to develop a new semi-analytical method to estimate the vaporization velocity based on the heat conduction equation and spreading data. The new method are compared to the existing one to show good agreement in magnitude and tendency. This agreement assures the new semi-analytical method to reliably estimate the vaporization velocity for the spreading pool without requiring the information about the spill rate and pool mass. The vaporization velocity obtained from the new method can be used as an input parameter for dispersion models and also an evaluation tool for existing spreading models. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.