USE OF CFD-MODELING FOR ESTIMATION OF DISTRIBUTION PARAMETERS OF CHEMICAL SUBSTANCES

Abstract

In this article we assess the possibility of the Fire Dynamic Simulator (FDS), software designed for simulating fires, usage in order to simulate and evaluate the processes of the spread of hazardous chemicals in the air in the case of a calculated accident at a chemically hazardous facility. We have considered and calculated an accident related to the spill of liquid chlorine with a temperature below the boiling point on the soil and its subsequent evaporation from the surface of the spill. The obtained data were compared with the results of the calculation of such an accident performed using the ALOHA software. It has been proved that FDS software can be used for CFD modeling of gas environments in the case of small accidents involving the release / spill of hazardous chemicals by modeling a section of surface several kilometers long. Such calculations will require a significant amount of RAM of the computing equipment, at the same time, they will impose strict requirements on the performance of the central processing unit compared to the performance of tasks related to fire simulation. However, it is necessary to use additional algorithms related to determining the intensity of emission of hazardous chemicals, for example in the case of their evaporation, which cannot be directly implemented by means of FDS. The results of the maximum values of the concentration of a hazardous chemical substance in the air obtained with the help of FDS are significantly different from the data obtained with the help of the ALOHA software. The ratio of calculated concentrations of NKR reaches 1300% with increasing distance from the source of evaporation. The dispersion of the NCR cloud simulated using FDS is much slower than that of the cloud calculated using ALOHA, which may be due to the lack of experience in modeling atmospheric processes in FDS, the need to refine wind profiles, and model boundary conditions. In the future, it may be promising to carry out research aimed at modeling atmospheric processes and a comparative analysis between the calculated values of the parameters of the distribution of hazardous chemicals obtained using CFD-modeling and the data obtained as a result of direct measurements during experimental studies.