Role of Gas Ventilation Pressure on the Stability of Airway Airflow in Underground Ventilation

Resumo

Coal mine ventilation is an extremely complicated system that can be disturbed by several factors. This report addresses the fact that the stabilization of airflow in the airways can be induced by gas ventilation pressure. The formation and characteristics of gas ventilation pressure are further elaborated and combined with the airflow stagnation accident that occurred in the Tangshan coal mine in China. Field tests, numerical simulations and experimental studies were conducted to verify the role of gas ventilation pressure on the stability of airway airflow. The results indicate that gas ventilation pressure is generated in inclined airways with gas accumulation, which can be regarded as an increment of natural ventilation pressure. Gas ventilation pressure can induce airflow stagnation or airflow reversals, especially in airways with relatively low airflow velocity. To maintain the stability of the airflow, mine ventilation structures must be strictly managed to ensure a higher airflow rate and velocity in those airways with gas emissions and avoid arranging airways with large dips.