Методы расчета дрейфа тяжелых облаков с учетом движения среды

Abstract

Peculiarities are considered related to the numerical integration of the diffusion equations for describing the formation and motion (drift) of explosive clouds formed on the territories of industrial facilities as a result of the accidental releases of combustible substances. The relevance of the study is associated with the fact that when the contents of an emergency release are mixed with an air, an explosive and flammable mixture is formed. The process of its combustion is determined by the volumetric concentration of the combustible substance. At concentrations below the lower concentration limit of ignition, combustion or explosion of the mixture is completely excluded. If the concentration of the mixture is between the lower and upper concentration limits of ignition, then there is an explosion. When the concentration of the mixture is above the upper concentration limit of ignition, a flash fire or a fireball occurs. Thus, the information is required on the parameters of the explosive mixture that may form due to the accidental release. Accidental releases can occur under the most adverse atmospheric environment and weather conditions. As a result, the focus of the article is on determining the parameters of an explosive cloud in the conditions of drift under the influence of a slight movement of the atmosphere (the most unfavorable scenario for the development of an accident). The results of numerical calculations of the diffusion equation with allowance for the mobility of the atmosphere are presented. The presence of a weak wind is the most unfavorable situation in terms of the drift of an explosive cloud. The methods and criteria are substantiated that allow obtaining the most correct results of calculating its motion.