RISK ASSESSMENT WITH THE USE OF THE MONTE-CARLO METHOD

Abstract

Purpose. This work involves the development of a numerical model for the calculation of chemical contamination zones in the event of ammonia accident at the pumping station, as well as a model for assessing the risk of damage and wound depth in the body in case of fragments scattering formed during the pipeline explosion at the pumping station. Methodology. To solve this problem, we used the mass transfer equation for the ammonia propagation in the air. A potential flow model is used to calculate the air flow velocity field in the presence of buildings at the ammonia pumping station. The numerical solution of the three-dimensional equation for the velocity potential is derived by the cumulative approximation method. When using this numerical model, the irregular field of wind flow velocity, the change in vertical atmospheric diffusion coefficient with altitude, the ammonia emission intensity, the emission point of the chemical substance were taken into account. A differential splitting scheme was used to numerically solve the ammonia transfer equation in the air. Physical splitting of the three-dimensional mass transfer equation to a system of equations describing the contaminant transfer in one coordinate direction is carried out beforehand. At each step of splitting, the unknown value of ammonia concentration is determined by an explicit scheme of point-to-point computation. A mathematical model for calculating the fragments scattering in case of emergency at the pumping station is considered. Findings. On the basis of the developed numerical model, a computational experiment was conducted to estimate the level of air pollution at the ammonia pumping station. The area of possible damage of people during the fragment scattering during the explosion at the ammonia pumping station was determined. Originality. A numerical model has been developed that allows calculating the chemical contamination zones in case of emergency ammonia emission at the pumping station. The model is complemented by assessment of impact zones in case of fragment scattering during the pumping station explosion. Practical value. Based on the developed mathematical model, a computer program was created, which allows performing serial calculations for determining the impact zones during emergency situations at the chemically hazardous objects. The mathematical model developed can be used to perform serial calculations during the development of emergency response plan for chemically hazardous objects.

Keywords

• atmosphere chemical pollution
• emergency emission
• mathematical modeling