Ventilation control of self-heating in retreating longwall coal mines

This paper summarizes the analyses of ventilation layouts for mines that experience both spontaneous combustion. The major focus is placed on the longwall coal mine layouts used in several countries. Each of the different layouts is modeled in the form of a ventilation network. The gob of a longwall panel is the most critical location for the occurrence of spontaneous combustion. Airflow leakage paths inside the gob are simulated by using a simplified grid-like network. Computer simulations with this model indicates that the W-system of ventilation is most effective in minimizing air leakage into the gob. However, the U-system. of ventilation, with pressure balancing behind the face support line, is also found promising for longwall panels. The magnitude of air leakage into the gob is observed to change with the advance or retreat of face, thus requiring appropriate balancing of pressure to maintain the leakage at a minimum.