Investigating the impact of gas emission uncertainty on airflow distribution in an auxiliary ventilation system using CFD and Monte-Carlo simulation

Gas emission in underground coal mines is of crucial importance. It is the potential cause of several health and safety issues such as gas explosion and gas poisoning. The emission of toxic and explosive gases in underground workings creates an unsafe environment, complicates the design of ventilation system, and increases the operating cost. The prediction of gas emission has long been associated with levels of uncertainty arising from parameters such as gas content and composition. This paper aims to identify the parameters affecting the uncertainty associated with the gas emission and determine the gas emission using the Monte Carlo simulation (MCS). A three-dimensional Computational Fluid Dynamics (CFD) model is developed to estimate the gas distribution and required airflow rate for ventilating the mine workings considering the gas content uncertainty. The CFD simulation is also carried out using the Monte Carlo modeling results to determine the effect of the uncertainty associated with the gas emission on the distribution of the required airflow rate. Several ventilation scenarios are investigated to determine the optimum ventilation air characteristics. It is found that for any specific design scenario, the ventilation system can be designed such that the mining operation can be carried out safely and with minimum cost.