Effect of source strength on the simulation of jet dispersion and hazard distances during accidental release of liquid CO2

Abstract

Accidental release of liquid CO2 can pose a certain risk to people, animals and equipment near release points. In addition to asphyxiation, cryogenic burns and dry-ice inhalation are potential risks that must be considered. In this study, a source model was established considering the formation of dry ice, which can quickly provide the inlet boundary condition for the computational fluid dynamics (CFD) model to simulate the jet dispersion of liquid CO2. The size distribution of the dry ice particles was described by the Rosin-Rammler expression. The effects of size distribution, initial pressure, liquid mass fraction and orifice size on the temperature, velocity, CO2 concentration, mass flow rate (nonsublimated dry ice) and survival distance were analysed. A quantitively risk assessment (QRA) method was used to evaluated the joint impact of source strength, dose-effect and impingement distance. The hazard distances associated with asphyxiation, cryogenic burn and dry ice inhalation were assessed. The results showed that the prediction errors of the mass flow rate using the source model were lower than 20 %. The temperature, velocity and CO2 concentration predicted by the CFD model agree well with the experimental results. The hazard distance was very dependent on and sensitive to the source strength and dose-effect.