Study on two-phase cloud dispersion from liquefied CO2 release

The knowledge of two-phase cloud dispersion mechanism from HLG (hazardous liquefied gas) release is the prerequisite for accurate assessment and precise rescue of such accidents. In this paper, an experi-ment of two-phase cloud dispersion from liquefied CO2 hole release is performed. The source terms, such as vapour mass fraction, release velocity and mean droplet diameter, are calculated based on thermody-namic theory. Taking phase transition of CO2 droplets to gas into account, CFD (computational fluid dynamics) model for two-phase cloud dispersion is established. The predicted cloud temperatures at the downstream agree well with the experimental data, with the maximum relative error of 5.8% and average relative error of 2.3%. The consequence distances in the downstream direction and in the cross-wise direction calculated through two-phase model are larger than those through single-phase model, with the relative differences of 57.8% and 53.6% respectively. CO2 concentration calculated by two-phase model is smaller in the vicinity of release hole, and larger beyond 0.135 m downstream. A smaller leakage rate results in a lower CO2 concentration and a higher cloud temperature.& COPY; 2023 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.