NUMERICAL MODELLING OF THE ACCUMULATION OF NITROGEN OXIDES IN DEAD-END AND MAIN WORKINGS.

The results of numerical simulation of the accumulation of nitrogen oxides in the deadend and main workings during the operation of the mucking and flitting device at the stages of loading and auxiliary operations are presented. The process of accumulation of nitrogen oxides is modeled on the basis of a previously developed two-stage methodological approach: the 1st stage is the calculation of aerodynamic parameters with applying a standard (1 - 0)-model turbulence and the 2nd stage is the solution of the convective-diffusion equation. Numerical experiments were performed for the ranges of air rate in a main working (6 ÷ 12 m3/sec), the length of a dead-end working (10 ÷ 25 m) and air leakage-suction (-0.05 ÷ +0.05 m3/sec) through the failure zone of a dead-end working with a length of 10 m. The results of the analysis of the accumulation of nitrogen oxides in the dead-end and main workings with variations of these parameters are presented. Significant pollution of the atmosphere of the main working was noted at the minimum length of the dead-end working. Almost linear dependences of concentration and mass rate on the amount of leakage-suction and time are predicted with the accepted values of leakage-suction and air rate. The approach used with minor modifications can be used both for other geometric dimensions of workings, and for various types of initial conditions of gas contamination of dead-end workings during blasting and operation of equipment with internal combustion engines. [ABSTRACT FROM AUTHOR]