Qualitative and quantitative investigation on concentration of indoor dense gas caused by leakage and diffusion

Abstract

A set of experimental system was built to study the concentration field change and influencing factors for the leakage and diffusion of indoor dense gas. CO2 was used in the experiment. CO2 gas tends to settle down after leakage. CO2 gas concentration values are disparate at different positions in the same height. It takes longer time to get the same CO2 gas concentration at higher positions than low positions. The concentration distribution is relatively approximate in the horizontal plane near the ground, while an uneven distribution is shown in the vertical plane. The concentration values increase with an increase in the leakage source strength at the positions which are lower than release source. Gas concentration is relatively stable at lower positions, while the fluctuation of gas concentration appears at higher positions. When the leakage source height is higher, the concentration near the ground reduces under the same condition. However, the whole space has a higher CO2 concentration which can generate greater risk. Incidence angle plays a great role in CO2 concentration. A theoretical calculation method was presented to predict CO2 concentration. The validation of the computation method was made by comparison of experimental data with calculation results. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 424–434, 2019